JP2000183230A - Mounting structure of high frequency circuit package - Google Patents

Abstract

(57) [Problem] To provide a conventional mounting structure of a high-frequency circuit package, there is a problem that reflection loss or radiation loss occurs at a connection portion and transmission characteristics of a high-frequency signal deteriorate. SOLUTION: A dielectric substrate 22 on which a lower ground conductor 23 and a mounting portion 22a are formed, a dielectric frame 24 on which an upper ground conductor 25 is formed, a line conductor 26 on a lower surface, and a side wall line conductor 27 on a side surface.
And a side wall ground conductor 28 on both sides of the side wall line conductor 27, and a through conductor 29 formed from the other end of the line conductor 26 to the upper surface of the dielectric substrate 22.
21, a mounting board including a substrate 34 on which a ground conductor 35 is formed on the lower surface side and a connection line conductor 36 formed on the upper surface, and a board-side ground through conductor 37 formed corresponding to the side wall ground conductor 28.
This is a mounting structure of a high-frequency circuit package in which the side wall line conductor 27 is mounted on a connection line conductor 33 and the side wall ground conductor 28 is connected to a substrate side ground through conductor 37. The grounding state of the connection portion is stabilized, and the reflection loss and the radiation loss can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency circuit package and a mounting substrate for accommodating high-frequency circuit components such as high-frequency semiconductor elements and high-frequency circuits that operate at high speed or in a high-frequency band.

[0002]

2. Description of the Related Art In a high-frequency circuit package for housing a high-frequency circuit such as a wireless communication device using a high-frequency signal in the MHz band or the GHz band or a high-frequency circuit component such as a high-frequency semiconductor element, the circuit or element is housed inside the package. High-frequency signal input / output section using line conductors for wiring in order to obtain good transmission characteristics of high-frequency signals by electrically connecting internal circuits and elements to external high-frequency circuits. Is formed. The mounting structure is configured by being surface-mounted on a mounting board which is an external electric circuit board.

Conventionally, such a mounting structure of a high-frequency circuit package has a structure as shown in a sectional view of FIG. 3A and a plan view of a main part thereof in FIG. 3B. Was.

In the high-frequency circuit package 1 shown in FIG. 3, a grounding conductor layer 3 is formed on the lower surface or inside, and a mounting portion 2a for mounting a high-frequency circuit component 8 such as a high-frequency semiconductor element on the upper surface, and this mounting portion A dielectric substrate 2 on which a line conductor 4 for high frequency signal transmission from the vicinity of 2a to the outer periphery is formed, and a so-called hermetic sandwiching a part of the line conductor 4 on the upper surface of the dielectric substrate 2 while surrounding the mounting portion 2a. A line conductor 4 formed on the side surface of the dielectric substrate 2 and extending to the outer periphery through the space between the dielectric substrate 2 and the dielectric frame 5; Side wall line conductor 6 for surface mounting, formed continuously and connected to
To form a signal input / output unit.

The high-frequency circuit component 8 mounted on the mounting portion 2a is electrically connected to the line conductor 4 by a conductive connection member (not shown) such as a bonding wire. After attaching a high-frequency circuit component 8 (not shown) to hermetically seal the high-frequency circuit component 8, the high-frequency circuit package 1 is mounted on a mounting substrate 9, and the side wall line conductor 6 is connected to the connection line conductor 12 of the mounting substrate 9. By the electrical connection, the high-frequency circuit component 8 inside the package 1 and the external electric circuit of the mounting board 2 are electrically connected.

Reference numeral 10 denotes a dielectric substrate constituting the mounting substrate 9, and reference numeral 11 denotes a ground conductor formed on the lower surface of the dielectric substrate 10.

Further, the side wall line conductor 6 of the high frequency circuit package 1 is formed under the side surface of the dielectric substrate 2, and is further formed on the lower surface of the dielectric substrate 2 by a line conductor continuously similar to the side wall line conductor 6. The mounting terminal conductor 7 is also formed to improve the mounting reliability.

[0008]

However, according to such a conventional mounting structure of a high-frequency circuit package, transmission of a high-frequency signal in the hermetic seal portion with respect to the line conductor 4 of the high-frequency circuit package 1 is in a microstrip mode. Since the mode is switched to the strip mode, there is a problem that impedance mismatch occurs in this portion, so that the reflection loss increases and the high-frequency characteristics of the transmission line deteriorate.

Further, since the characteristic impedance of the line conductor 4 is lower than that before and after the line conductor 4 in accordance with the dielectric constant of the dielectric frame 5 existing above the line conductor 4, there is a mismatch in characteristic impedance between them. This causes a problem that the reflection loss of the high-frequency signal increases and the transmission characteristics of the high-frequency signal deteriorate.

In such a conventional structure for mounting a package for a high-frequency circuit, a side wall line is formed on the line conductor 4 on the side surface of the dielectric substrate 2 as a terminal electrode for mounting on the connection line conductor 12 of the mounting substrate 9. Since the conductor 6 is formed continuously, the presence of the side wall line conductor 6 reduces the capacitance component, or increases the inductance component to increase the impedance and increase the reflection of the high frequency signal. There has been a problem that signal transmission characteristics are degraded. In particular, when the length of the side wall line conductor 6 is increased, the impedance is remarkably increased, and there is a problem that the transmission characteristics of a high-frequency signal are greatly reduced.

Further, there is a problem that characteristic impedance mismatching occurs at a connection portion between the high-frequency circuit package and the mounting board, which also increases the reflection of high-frequency signals.

The present invention has been devised in view of the problems of the prior art described above, and has as its object to provide a surface mount type having a side wall line conductor as a signal input / output unit for surface mount on a side surface of a dielectric substrate. It is an object of the present invention to provide a mounting structure for a high-frequency circuit package having a low reflection characteristic with respect to a high-frequency signal and having good transmission characteristics.

[0013]

SUMMARY OF THE INVENTION A high-frequency circuit package according to the present invention has a dielectric substrate having a lower grounding conductor formed therein and a mounting portion for mounting a high-frequency circuit component formed on an upper surface thereof. A dielectric frame having an upper grounding conductor formed on the upper surface thereof and being joined to the upper surface of the dielectric frame, and a dielectric frame formed on the lower surface of the dielectric substrate and corresponding to a position corresponding to the inside of the dielectric frame. And a side wall line conductor formed continuously on the side surface of the dielectric substrate with the line conductor, the length of which is equal to or less than a quarter of the wavelength of a high-frequency signal transmitted by the line conductor. And a side wall ground conductor formed at a position on both sides of the side wall line conductor at a distance of one half or less of the wavelength of the high frequency signal and electrically connected to the upper ground conductor, and the other of the line conductors From inside the dielectric frame A high-frequency circuit package comprising a through conductor formed over the upper surface of the dielectric substrate, a grounding conductor formed on the lower surface side, and a connection line conductor electrically connected to the side wall line conductor on the upper surface. A mounting substrate comprising: a substrate made of a formed dielectric; and a substrate-side ground through conductor formed from the ground conductor to the upper surface of the substrate at a position corresponding to the side wall ground conductor on both sides of the connection line conductor. And the side wall line conductor is electrically connected to the connection line conductor, and the side wall ground conductor is electrically connected to the substrate side ground through conductor.

In the above structure, the package for a high-frequency circuit according to the present invention may be arranged such that the high-frequency circuit package has a half or less wavelength of the high-frequency signal from the through conductors on both sides of the line conductor. A ground through conductor extending from an upper surface to a lower surface of the dielectric substrate electrically connected to the lower ground conductor is formed at a distance.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIGS. 1A and 1B are a cross-sectional view and a plan view of a main part, respectively, showing an embodiment of a high-frequency circuit package according to the present invention.

In these figures, 21 is a high-frequency circuit package, 22 is a dielectric substrate having a mounting portion 22a on which a high-frequency circuit component 32 is mounted, and 23 is a lower ground conductor formed therein. .

Reference numeral 24 denotes a dielectric frame which is joined on the dielectric substrate 22 so as to surround the mounting portion 22a and serves as a side wall of a housing portion for housing the high-frequency circuit component 32, and 25 is an upper portion formed on the upper surface thereof. It is a ground conductor. These dielectric substrate 22 and dielectric frame
24 constitutes a container of a package body for accommodating the high-frequency circuit component 32. And this dielectric frame 24
The inside is hermetically sealed by joining a lid (not shown) to the upper surface of the device. Further, depending on the specifications of the high-frequency circuit package 21, the high-frequency circuit component 32 may be sealed with a sealing resin without using a lid.

Reference numeral 26 denotes a line conductor for high-frequency signal transmission formed on the lower surface of the dielectric substrate 22 from the position corresponding to the vicinity of the mounting portion 22a inside the dielectric frame 24 to the outer periphery. To form a plurality of or dielectric substrates 22 in various directions. Such a line conductor 26 and a dielectric substrate
A transmission line having a microstrip line structure is constituted by 22 and the lower ground conductor 23. Note that this line conductor 26
May be provided with coplanar conductors on both sides thereof to form a transmission line having a coplanar line structure.

Reference numeral 27 denotes a side wall line conductor formed continuously on the side surface of the dielectric substrate 22 with the line conductor 26. The side wall line conductor 27 is electrically connected to a connection line conductor 36 of a mounting substrate 33 which is an external electric circuit. The high-frequency circuit component 32 inside the package and the external electric circuit are electrically connected. This side wall conductor 27
Is set to be less than or equal to a quarter of the wavelength of the high-frequency signal transmitted by the line conductor 26 using the high-frequency circuit component 32. As a result, it is possible to minimize the loss due to the length of the transmission line, so that the sidewall component does not cause a decrease in the capacitance component or an increase in the inductance component, which is a problem in the high-frequency characteristics. In addition, it is possible to prevent the transmission line from becoming high impedance, increasing the reflection of the high-frequency signal and deteriorating the transmission characteristics of the high-frequency signal. Such an effect is particularly effective when the frequency of the high-frequency signal is 10 GHz or more. In particular, for a high-frequency signal having a frequency of 30 GHz or more, the impedance is increased even in such a higher-frequency region by setting the length of the side wall line conductor 27 to 1/8 or less of the wavelength of the high-frequency signal. Can be effectively suppressed, and the high-frequency circuit package 21 having good reflection characteristics and high-frequency characteristics can be obtained.

Such a side wall line conductor 27 is usually set to a length substantially equal to the length of the side surface (height of the side wall) of the dielectric substrate 22. It may be formed on the side surface of the dielectric substrate 22 as shorter than the length. As a result, both the strength required for the dielectric substrate 22 and the high-frequency characteristics required for the transmission line for transmitting a high-frequency signal are ensured, and the high-frequency circuit package 21 having excellent reliability can be obtained. The lower ground conductor 23 and the side wall line conductor 26
It is sufficient that an electrical insulation is provided between them and a distance that does not adversely affect high-frequency characteristics is provided.

Reference numeral 28 denotes a side wall line conductor 27 on both sides of the side wall line conductor 27 on the side surfaces of the dielectric substrate 22 and the dielectric frame 24.
And a side wall ground conductor electrically formed with the upper ground conductor 25 at a distance of not more than half of the wavelength of the high frequency signal. Such a side wall ground conductor 28 is formed, for example, directly on the side surface of the dielectric substrate 22 and the dielectric frame 24, or a concave portion (so-called castellation) provided on the side surface.
Is formed by applying a conductor layer to the surface of the substrate.

Numeral 29 corresponds to the other end of the line conductor 26, that is, the end on the side corresponding to the vicinity of the mounting portion 22a inside the dielectric frame 24, from the vicinity of the mounting portion 22a inside the dielectric frame 24. A high-frequency circuit component 32 is electrically connected to the through conductor 29 via the electrode pad 30 or directly at the upper end thereof. Incidentally, the line conductor 26 and through conductor 29, respectively depending on the value of the relative dielectric constant epsilon _r of the dielectric substrate 22, the characteristic impedance Z ₀ of the desired width, diameter and length so that the value is set You.

Reference numeral 31 denotes a through conductor on both sides of the line conductor 26.
A dielectric substrate 22 electrically connected to the lower ground conductor 23 at a distance of less than half the wavelength of the high-frequency signal from 29.
Is a ground through conductor extending from the upper surface to the lower surface of the ground. The ground through conductor 31 may be provided according to the required high-frequency characteristics, and the distance between the ground through conductor 31 and the line conductor 26 is determined by the length of the through conductor.
The distance may be set within a range from 29 to a half or less of the wavelength of the high-frequency signal indicated by a dashed line in FIG.

Further, a plurality of grounding through conductors 31 may be formed on both sides of the line conductor 26, respectively. On the lower surface of the dielectric substrate 22, both sides of the line conductor 26 are grounded on the same plane so as to form a so-called coplanar line structure. Conductors may be provided, and these may be connected to the ground through conductor 31.

By forming such a grounding through conductor 31, it is possible to supplement a capacitance component to the high impedance through conductor 29, so that impedance mismatch in the through conductor 29 can be prevented. as a result,
The impedance mismatch in the electrical connection between the high-frequency circuit component 32 and the external electric circuit can be effectively suppressed, the deterioration of the transmission characteristics of the high-frequency signal can be suppressed, and the low-reflection loss high-frequency circuit package 21 can be used. can do. The ground through conductor 31 may be formed of a through-hole conductor, a via conductor, or the like, similarly to the through conductor 29.

Reference numeral 32 denotes a high-frequency circuit component such as a high-frequency semiconductor device or a high-frequency circuit mounted on the mounting portion 22a. The electrode pad 30 or the through conductor 29 is electrically connected to the electrode pad 30 or the through conductor 29 by wire bonding or ribbon bonding (not shown) or so-called bump connection. Connected.

On the other hand, 33 is a mounting substrate, 34 is a substrate made of a dielectric material, 35 is a lower surface side of the substrate 34, here a ground conductor formed on the lower surface, and 36 is a side wall line conductor 27 electrically connected. And a connection line conductor that forms part of an external electric circuit (not shown). This connection line conductor 36 is used as a side wall line conductor.
By electrically connecting with the line conductor 27 and the line conductor 26, the high-frequency circuit component 32 and the external electric circuit are electrically connected. Note that the ground conductor 35 may be formed inside the substrate 34 as long as it is on the lower surface side of the substrate 34.

Reference numeral 37 denotes a board-side ground through conductor formed from the ground conductor 35 to the upper surface of the board 34 at a position corresponding to the side wall ground conductor 28 on both sides of the connection line conductor 36. By electrically connecting the substrate-side grounded through conductors 37 to the side wall grounded conductors 28, the high-frequency circuit package 21 is formed.
The upper ground conductor 25 and the ground conductor 35 of the mounting board 33 surround the connection portion between the side wall line conductor 27 and the connection line conductor 36 via the side wall ground conductor 28 and the board side ground through conductor 37. It will be electrically connected.

According to such a mounting structure of the high-frequency circuit package of the present invention, the high-frequency circuit package 21 has the high-frequency wave applied to the through conductor 29 located near the mounting portion 22a inside the dielectric frame 24. The circuit components 32 are electrically connected,
A connection line conductor 36 of a mounting substrate 33 as an external electric circuit is electrically connected from the through conductor 29 to a side wall line conductor 27 connected via a line conductor 26 formed on the lower surface of the dielectric substrate 22. Therefore, there is no switching from microstrip mode to strip mode as in the case of conventional line conductors that pass through a hermetic seal, so that impedance mismatch does not occur, reflection loss increases, and the high-frequency characteristics of the transmission line increase. Does not deteriorate.

The length of the side wall line conductor 27 of the high frequency circuit package 21 is a quarter of the wavelength of the high frequency signal transmitted by the line conductor 26 using the high frequency circuit component 32.
From the following, it is possible to minimize the loss due to the length of the transmission line.
Therefore, a decrease in the capacitance component and an increase in the inductance component, which are problems in the high frequency characteristics, do not occur.
As a result, it is possible to prevent the transmission line from becoming high impedance, increasing the reflection of the high-frequency signal, and deteriorating the transmission characteristics of the high-frequency signal.

According to the mounting structure of the high-frequency circuit package of the present invention, the line conductor 26 and the side-wall line conductor of the high-frequency circuit package 21 for transmitting a high-frequency signal.
27 and the connecting line conductor 36 of the mounting substrate 33 are connected to the connecting portion of the high-frequency transmission line between the dielectric substrate 22 of the package 21 and the substrate 34 made of the dielectric of the mounting substrate 33.
The ground conductor 35 on the board side is connected to the dielectric board via the board 34
Arrange the upper ground conductor 25 via 22 and the dielectric frame 24,
Further, side wall ground conductors 28 are provided on both sides thereof, and further, a board side ground through conductor electrically connected to a ground conductor 35 of the mounting board 33 side on a substrate 34 immediately below the side wall ground conductor 28, respectively.
37, the line conductor 26 and the side wall line conductor
The line configuration of the portion where 27 is connected to the connection line conductor 36 of the mounting board 33 on the side surface of the package 21 has a pseudo waveguide structure surrounded by a ground conductor. As a result, the grounding state of the grounding conductor surrounding the transmission line is stabilized,
In addition, the occurrence of higher-order modes can be suppressed to reduce the reflection loss, and the radiation loss can be suppressed by the electromagnetic wave shielding effect. As a result, it is possible to improve the transmission characteristics of the high-frequency signal at the connection portion of the high-frequency signal with low loss and good performance as the mounting structure of the high-frequency circuit package.

Further, in the high-frequency circuit package 21, a dielectric electrically connected to the lower grounding conductor 23 at a distance of not more than half the wavelength of the high-frequency signal from the through conductor 29 on both sides of the line conductor 26. When the ground through conductor 31 extending from the upper surface to the lower surface of the body substrate 22 is formed, an appropriate capacitance component can be provided between the line conductor 26 and the ground through conductor 31, so that the impedance in the through conductor 29 can be increased. Mismatch can be prevented.

The dielectric substrate 22 of the high-frequency circuit package 21 in the mounting structure of the high-frequency circuit package of the present invention.
The dielectric frame 24 and the substrate 34 of the mounting substrate 33 are made of, for example, a ceramic material such as alumina ceramics or aluminum nitride ceramics, an inorganic material such as glass ceramics, or a material such as PTFE (polytetrafluoroethylene), glass epoxy, or polyimide. A resin material or the like is used. For example, in the case of a glass ceramic, a concave portion or a through hole serving as a through conductor is formed in a green sheet of the glass ceramic as necessary, and a lower ground conductor 23, an upper ground conductor 25, a line conductor 26,
The metal paste which becomes the side wall line conductor 27, the side wall ground conductor 28, the ground conductor 35, the connection line conductor 36 and the through conductor 29, the ground through conductor 31, and the board side ground through conductor 37 is printed and filled,
These green sheets are stacked one on top of the other
What is necessary is just to manufacture by baking integrally at 00 degreeC.

Alternatively, the lower ground conductor 23 and the upper ground conductor having a predetermined pattern may be formed on the upper surface, side surfaces, and lower surface of the fired dielectric substrate 22, dielectric frame 24, and substrate 34 by various thin film methods or printing and firing methods. 25 ・ Line conductor 26 ・ Side wall conductor 27 ・ Side wall ground conductor 28 ・ Ground conductor 35 ・ Connection line conductor 36
And through conductor 29, ground through conductor 31, board side ground through conductor 37
May be formed.

The shapes and dimensions (thickness, width, and length) of the dielectric substrate 22, the dielectric frame 24, and the substrate 34 may be appropriately set according to the frequency and characteristic impedance of the high-frequency signal used. .

It should be noted that the same material may be used for the dielectric frame 24 and the dielectric substrate 22 in general, but the dielectric constant of the dielectric frame 24 and the dielectric constant of the dielectric substrate 22 may be reduced by using different materials. May be different. In this case, for example, the dielectric constant of the dielectric frame 24 is preferably lower than that of the dielectric substrate 22, and the dielectric constant of the dielectric frame 24 is preferably as close as possible to the vacuum dielectric constant. This is preferable in that the change in the propagation mode of the high-frequency signal at the junction between the dielectric substrate 22 and the dielectric frame 24 and the other portions is reduced, and the transmission loss is reduced.

A lower ground conductor 23, an upper ground conductor 25, a line conductor 26, a side wall line conductor 27, a side wall ground conductor 28, a ground conductor 35,
Connection line conductor 36 and through conductor 29 / ground through conductor 31
As a conductor for forming the board-side ground through conductor 37,
Tungsten, copper, nickel, gold, chrome, nichrome,
Tantalum / titanium / palladium nitride, an alloy thereof, or the like may be used, and the formation may be performed by various thin film methods, a combination of the thin film method and the photolithography method, or a printing / firing method. These thickness, width, diameter (cross-sectional shape and dimensions), and length may be basically set as appropriate according to the frequency and characteristic impedance of the transmitted high-frequency signal.

The upper ground conductor 25, the side wall ground conductor 28, and the ground conductor 35 may be formed by using the same material as the line conductor 26 and the lower ground conductor 23 by the same method. Besides forming as a coating layer, it may be formed by attaching another conductive member, for example, a metal plate or a metal block.

The through conductor 29, the ground through conductor 31, and the substrate side ground through conductor 37 are formed by burying a metal plate, a metal rod, a metal pipe or the like in addition to forming them as through-hole conductors or via conductors. May be.

In the side wall ground conductor 28 formed at a distance of less than half the wavelength of the high frequency signal from the side wall line conductor 27, the gap g between them is represented by the following formula. If the value is smaller than the gap g _0, the attenuation of the high-frequency signal due to resonance can be avoided, so that the transmission characteristic at the frequency of the high-frequency signal transmitted through the connection between the side wall line conductor 27 and the connection line conductor 36 is reduced. Can be excellent. g ₀ = C ₀ / 2f · √ε _reff where g ₀ is the gap between the side wall ground conductors 28 at which resonance occurs, C ₀ is the speed of light, f is the frequency of the high frequency signal, ε _reff is the dielectric frame 24 and the dielectric It is a relative dielectric constant obtained by synthesizing the relative dielectric constant of the body substrate 22.

When the side wall line conductor 28 is formed in the concave portion on the side surface of the dielectric substrate 22 and the dielectric frame 24, the deeper the concave portion is formed toward the inside of the dielectric frame 24, the longer the distance. Due to the pseudo waveguide structure, the grounding state becomes more stable, and the transmission characteristics of the high-frequency signal can be further improved. Therefore, the side wall ground conductor
In the case where 28 is formed in a concave portion on the side surface of dielectric substrate 22 and dielectric frame 24, it is desirable to form the concave portion as deep as possible within a range where airtight sealing inside package 21 can be maintained.

Using the high-frequency circuit package 21 as described above, a high-frequency circuit component 32 is mounted on the mounting portion 22a,
The electrode is electrically connected to the through conductor 29 located inside the dielectric frame 24 via a bonding wire, a bonding ribbon, a connection bump, or the like, and the upper surface of the dielectric frame 24 is made of Fe-Ni-Co or Fe- such as Fe-Ni42 alloy
Ni alloy, oxygen-free copper, aluminum, stainless steel, Cu
-W alloy, Cu-Mo alloy, etc.
The high-frequency circuit component 32 is formed by attaching with a low melting point metal brazing material such as uSn brazing or the like or a high melting point metal brazing material such as AuGe brazing or by seam welding (welding) or by sealing with a sealing resin. package
It is housed in a hermetically sealed manner inside 21 and becomes a high-frequency circuit device as a product.

Then, this is mounted on a mounting board 33 which is an external electric circuit board, and the side wall line conductor 27 is connected to the connection line conductor 36 and the side wall ground conductor 28 is connected to the board side ground through conductor 37, respectively. By bonding via a ball lead or surface mount reflow, etc., the mounting structure of the high frequency circuit package of the present invention is formed, and the high frequency circuit components 32 inside the package 21 and the external electric circuit are electrically connected to each other. A circuit device will be used.

[0045]

A package for high frequency circuit according to the mounting structure of the present invention shown in EXAMPLES 1, on the lower surface of the dielectric substrate 22 of the dielectric constant to form a lower ground conductor 23 epsilon _r is 9 therein, the dielectric frame A line conductor 26 having a line width of 100 μm from the position corresponding to the vicinity of the mounting portion 22a inside the body 24 to the outer periphery of the dielectric substrate 22 was formed.

The dielectric substrate 22 and the dielectric frame 24
On the side of (relative permittivity ε _r = 9), the line width is 150 μm and the length is 400 μm (80
(Corresponding to 1 GHz) side wall line conductor 27 is formed continuously with line conductor 26 on the outer periphery of dielectric substrate 22. On the other hand, the mounting portion 22a inside the dielectric frame 24 from the other end of the line conductor 26
A through conductor 29 having a diameter of 100 μm was formed from the upper surface to the lower surface of the dielectric substrate 22 at a position corresponding to the vicinity.

Further, the dielectric substrate 22 and the dielectric frame 24
The gap between the side wall line conductor 27 and the side wall line conductor 27 on the side surface of the high frequency signal is not more than half of the wavelength of the high frequency signal.
With the line width set to 0 μm and the line width set to 200 μm, the side wall ground conductor 28 electrically connected to the upper ground conductor 25 formed on the upper surface of the dielectric frame 24 was formed.

The lower ground conductor extends from the upper surface to the lower surface of the dielectric substrate 22 at a distance of 1 mm, which is less than half the wavelength of the high-frequency signal, from the through conductor 29 on both sides of the line conductor 26.
A ground through conductor 29 electrically connected to 23 was formed.

Thus, a sample A of the high-frequency circuit package 21 according to the mounting structure of the present invention was manufactured.

On the other hand, as the mounting substrate 33, the relative permittivity ε _r
= 2.6 and a thickness of 400 μm on the upper surface of the substrate 34, a connecting line conductor 36 having a coplanar line structure having a line width of 900 μm and a distance of 250 μm from the ground conductor is formed on the upper surface of the substrate 34. The ground conductor 35 on the lower surface of the substrate 34 is electrically connected to the same potential by using the substrate-side ground through conductor 37. In addition, the line width of the connecting line conductor 36 is set to 350 μm so that the portion corresponding to the lower surface of the dielectric substrate 22 becomes 50Ω.
The distance from the ground conductor was set to 300 μm.

Thus, a sample A of the mounting board 33 according to the mounting structure of the present invention was manufactured.

Then, the sample A of the high-frequency circuit package is placed on the sample A of the mounting board, and the side wall line conductor 27 is connected to the connection line conductor 36 and the side wall ground conductor 28 is connected to the substrate side ground through conductor 37. It was electrically connected by brazing to obtain a sample A of the mounting structure of the high-frequency circuit package of the present invention.

Next, a sample B was prepared by removing the side wall grounding conductor 28 from the sample A of the above-described high frequency circuit package. A sample B was prepared by removing the board-side ground through conductor 37 from the sample A of the mounting board.

Then, the sample B of the high-frequency circuit package was placed on the sample B of the mounting board, and the side wall line conductor 27 was electrically connected to the connection line conductor 36 in the same manner as described above. A sample B having a mounting structure of a circuit package was obtained.

[0055] For the samples A · B, seeking the frequency characteristics of S parameters by the three-dimensional structural analysis simulator (HFSS), to obtain a frequency characteristic of a reflection coefficient S _11. The result is shown in FIG. FIG. 2 is a diagram showing the frequency characteristics of these reflection coefficients, where the horizontal axis represents frequency (unit: GHz).
The vertical axis indicates the reflection coefficient (unit: dB), and the solid line in the figure indicates the characteristic curve for the reflection coefficient of the sample A, and the broken line indicates the characteristic curve for the reflection coefficient of the sample B.

As can be seen from FIG. 2, in sample B,
Deterioration of the reflection characteristics was observed at 30 GHz, but the deterioration was eliminated in the sample A, and favorable reflection characteristics were obtained even in the millimeter wave band.

According to the result, according to the mounting structure of the high-frequency circuit package of the present invention, since the connection portion of the high-frequency signal is formed as the pseudo waveguide structure, the reflection is lower in the high-frequency band than in the conventional mounting structure. It was confirmed that the device had excellent transmission characteristics.

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, the line conductor 26, the side wall line conductor 27, the connection line conductor 36, and the side wall ground conductor
28. A plurality of substrate-side ground through conductors 37 may be provided as necessary. In addition, by using leads for the connection line conductor 36, mounting reliability can be improved.

[0059]

According to the mounting structure of the high-frequency circuit package of the present invention, the high-frequency circuit component is electrically connected to the through conductor whose upper end is located inside the dielectric frame and near the mounting portion. And the connection line conductor of the mounting board is electrically connected to the side wall line conductor connected from the through conductor to the side wall line conductor formed on the lower surface of the dielectric substrate. There is no switching from microstrip mode to strip mode as in the case of line conductors passing through the hermetic seal part in the package for the package, so there is no impedance mismatching, reflection loss increases, and the high-frequency characteristics of the transmission line deteriorate. I won't.

Further, since the length of the side wall line conductor of the high frequency circuit package is not more than 以下 of the wavelength of the high frequency signal, it is possible to minimize the loss due to the length of the transmission line. Because of this, the side wall line conductor does not cause a decrease in capacitance component or an increase in inductance component, which is a problem in high frequency characteristics, and as a result, the transmission line has a high impedance and the reflection of high frequency signals increases, so that high frequency Signal transmission characteristics do not deteriorate.

According to the mounting structure of the high-frequency circuit package of the present invention, the ground conductor on the board side is connected to the connection portion of the high-frequency transmission line for transmitting the high-frequency signal via the board of the mounting board. An upper ground conductor is arranged via a dielectric substrate and a dielectric frame, and side wall ground conductors are provided on both sides of the upper ground conductor. Since the substrate-side grounded through conductors connected to each other are formed, the line configuration of the connection portion of the high-frequency transmission line becomes a pseudo waveguide structure surrounded by the grounding conductor. As a result, it is possible to stabilize the grounding state of the grounding conductor surrounding the transmission line, suppress the occurrence of higher-order modes, reduce the reflection loss, and suppress the radiation loss by the electromagnetic wave shielding effect. As a result, a high-frequency circuit package mounting structure with low loss and good high-frequency signal transmission characteristics at the high-frequency signal connection portion can be obtained.

Further, in the high-frequency circuit package, the upper surface of the dielectric substrate electrically connected to the lower ground conductor at a distance of less than half the wavelength of the high-frequency signal from the through conductor on both sides of the line conductor. In the case where a ground through conductor extending from the lower surface to the lower surface is formed, an appropriate capacitance component can be provided between the line conductor and the ground through conductor.
The impedance mismatch in the through conductor can be prevented.

As described above, according to the present invention, a surface mounting type high frequency circuit package having side wall conductors as signal input / output portions for surface mounting on the side surfaces of the dielectric substrate is used for mounting high frequency signals. On the other hand, a mounting structure of a high-frequency circuit package having low reflection characteristics and good transmission characteristics can be provided.

[Brief description of the drawings]

FIGS. 1A and 1B are a cross-sectional view and a plan view of a main part, respectively, showing an example of an embodiment of a mounting structure of a high-frequency circuit package according to the present invention.

FIG. 2 is a diagram showing a frequency characteristic of a reflection coefficient in a mounting structure of a high-frequency circuit package.

FIGS. 3A and 3B are a cross-sectional view and a main part plan view, respectively, showing an example of a mounting structure of a conventional high-frequency circuit package.

[Explanation of symbols]

 21: High frequency circuit package 22: Dielectric substrate 22a: Mounting part 23: Lower ground conductor 24: Dielectric frame 25 ...・ Top ground conductor 26 ・ ・ ・ ・ ・ Line conductor 27 ・ ・ ・ ・ ・ ・ Side wall conductor 28 ・ ・ ・ ・ ・ ・ Side wall conductor 29 ・ ・ ・ ・ ・ Through conductor 31 ・ ・ ・ ・ ・ Ground through conductor 32 ・ ・・ ・ ・ High frequency circuit parts 33 ・ ・ ・ ・ ・ ・ Mounting board 34 ・ ・ ・ ・ ・ ・ Substrate 35 ・ ・ ・ ・ ・ ・ Ground conductor 36 ・ ・ ・ ・ ・ ・ Line conductor for connection 37 ・ ・ ・ ・ ・ ・ Ground through conductor on board side

Claims (2)

[Claims] 1. A dielectric substrate having a lower grounding conductor formed therein and a mounting portion for mounting a high-frequency circuit component formed on an upper surface thereof, and a dielectric substrate joined to the upper surface of the dielectric substrate so as to surround the mounting portion. A dielectric frame having an upper ground conductor formed thereon, a line conductor formed on a lower surface of the dielectric substrate and extending from a position corresponding to the inside of the dielectric frame to an outer periphery, and a side surface of the dielectric substrate. A side wall line conductor formed continuously with the line conductor, the length of which is equal to or less than a quarter of the wavelength of the high frequency signal transmitted by the line conductor; A side wall ground conductor formed at a distance of one-half wavelength or less and electrically connected to the upper ground conductor, and the dielectric on the inside of the dielectric frame from the other end of the line conductor; Through conductor formed over the top surface of the body substrate A high-frequency circuit package, comprising: a substrate made of a dielectric having a ground conductor formed on a lower surface side and a connection line conductor formed on an upper surface to be electrically connected to the side wall line conductor; And a substrate side ground through conductor formed from the ground conductor to the upper surface of the substrate at a position corresponding to the side wall ground conductor on both sides of the mounting substrate, and the side wall line conductor is connected to the connection line conductor. And the side wall ground conductor is electrically connected to the board-side ground through conductor, respectively. 2. The high-frequency circuit package is electrically connected to the lower ground conductor at a distance of not more than half the wavelength of the high-frequency signal from the through conductor on both sides of the line conductor. The mounting structure for a high-frequency circuit package according to claim 1, wherein a ground through conductor extending from an upper surface to a lower surface of the dielectric substrate is formed.