JP2000164743A - High-frequency circuit package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface-mount high-frequency circuit package which is equipped with a sidewall line conductor as a signal input/output on the side of a dielectric board and low in reflection and high in transmission properties to high-frequency signals. SOLUTION: A high-frequency circuit package is composed of a dielectric board 1, equipped with a ground conductor layer 2 formed on its underside or inside it and a mounting region 1a, where a high-frequency circuit part 6 is mounted and a line conductor 3 is provided, extending from around the mounting region 1a to the periphery, a dielectric frame 4 jointed to the top surface of the dielectric board 1, and a sidewall line conductor 5 formed on the side of the dielectric board 1 extending continuously from the line conductor 3, where the sidewall line conductor 5 is formed 1/4 or below as long as the wavelength of high-frequency signals. A high-frequency circuit package of this constitution can be lessened in reflection properties and enhanced in transmission properties restraining the sidewall line conductor 5 from increasing in impedance.

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 for mounting and housing high frequency circuit components in a microwave band or a millimeter wave band, and more particularly to a high frequency circuit suitable for surface mounting on an external electric circuit board. It is related to a package for use.

[0002]

2. Description of the Related Art In a high-frequency circuit package for accommodating a high-frequency circuit or a high-frequency semiconductor element such as a wireless communication device using a high-frequency signal in a MHz band or a GHz band, the high-frequency circuit or the high-frequency semiconductor element is accommodated inside the package. In order to obtain good transmission characteristics for high-frequency signals by electrically connecting internal circuits and elements to external circuits, signal input / output units using wiring using line conductors It is formed.

Conventionally, in such a package for a high-frequency circuit, a grounding conductor layer is formed on the lower surface or inside, and a mounting portion for mounting a high-frequency circuit component such as a high-frequency semiconductor element on the upper surface and an outer peripheral portion near the mounting portion. A dielectric substrate on which a line conductor for high-frequency signal transmission leading to is formed, is joined to the upper surface of the dielectric substrate so as to surround a mounting portion and form a so-called hermetic seal portion with a part of the line conductor interposed therebetween. For the surface mounting, which is continuously formed and connected to the line conductor formed up to the outer periphery through the dielectric substrate and the dielectric frame on the side surface of the dielectric substrate. A signal input / output unit is formed by forming a side wall line conductor. Then, the high-frequency circuit package is mounted on an external electric circuit, and the side wall line conductor is electrically connected to the connection conductor of the external electric circuit, so that the high-frequency circuit components inside the package and the external electric circuit are electrically connected. Was connected.

Further, a side wall line conductor is formed up to the side of the dielectric substrate, and a mounting terminal conductor is formed on the lower surface of the dielectric substrate by a line conductor similar to the side wall line conductor. It was also used to enhance sex.

[0005]

However, in the above-mentioned conventional high-frequency circuit package, the tip of the line conductor extending from the vicinity of the mounting portion to the outer periphery of the dielectric substrate is provided with
Since the side wall line conductor is connected to the outer wall of the package, that is, outside the dielectric frame, on the side wall of the dielectric substrate, the existence of the side wall line conductor in the transmission line for high-frequency signal transmission by these line conductors and the side wall line conductors As a result, a capacitance component is reduced and an inductance component is increased. As a result, the transmission line has a high impedance, and the reflection of a high-frequency signal is increased. As a result, the transmission characteristics of the high-frequency signal are reduced. In particular,
When the length of the side wall line conductor is increased, the impedance is remarkably increased, and there is a problem that the transmission characteristics of a high-frequency signal are significantly reduced.

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 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. Another object of the present invention is to provide a high-frequency circuit package having low reflection characteristics for high-frequency signals and good transmission characteristics.

[0007]

According to the high frequency circuit package of the present invention, a ground conductor layer is formed on the lower surface or inside thereof.
A dielectric substrate having an upper surface on which a mounting portion for mounting high-frequency circuit components and a line conductor extending from the vicinity of the mounting portion to the outer periphery; and a portion of the line conductor surrounding the mounting portion on the upper surface of the dielectric substrate A dielectric frame joined across the
The liner conductor is formed on a side surface of the dielectric substrate and a side wall line conductor formed continuously, and the length of the side wall line conductor is a quarter of the wavelength of a high frequency signal transmitted by the line conductor. It is characterized by the following.

Further, in the package for a high-frequency circuit according to the present invention, in the above-mentioned structure, the dielectric substrate is located at a distance of not more than half the wavelength of the high-frequency signal from the side wall line conductor on both sides of the line conductor. Wherein a ground through conductor is formed at least from the upper surface to the ground conductor layer.

Further, the package for a high-frequency circuit according to the present invention is characterized in that in each of the above structures, a mounting terminal conductor is formed continuously with the side wall line conductor on a lower surface of the dielectric substrate. .

According to the high-frequency circuit package of the present invention, the length of the side-wall line conductor is less than one-fourth of the wavelength of the high-frequency signal transmitted by the line conductor using the high-frequency circuit component. Since the loss due to the length of the transmission line can be minimized, the side wall conductor does not cause a decrease in the capacitance component or an increase in the inductance component, which is a problem in high-frequency characteristics. Does not become high impedance and the reflection of the high-frequency signal increases, so that the transmission characteristic of the high-frequency signal does not deteriorate.

Further, in the case where the ground through conductor is formed from the upper surface of the dielectric substrate to at least the ground conductor layer at a distance of not more than half the wavelength of the high frequency signal from the side wall line conductor on both sides of the line conductor. Since an appropriate capacitance can be provided between the line conductor and the ground through conductor, impedance mismatch in the side wall line conductor of the package can be prevented.

Further, when the mounting terminal conductor is formed continuously with the side wall line conductor on the lower surface of the dielectric substrate, the connection strength to an external electric circuit can be increased and the mounting reliability can be improved.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A high-frequency circuit package according to the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B are a sectional view and a plan view, respectively, showing an example of an embodiment of a high-frequency circuit package according to the present invention. In FIG. 1, 1
Is a dielectric substrate, 1a is a mounting portion formed on the upper surface thereof, 2a
Is a ground conductor layer formed inside the dielectric substrate 1.
In this example, a concave portion is formed in the center of the upper surface of the dielectric substrate 1 and the mounting portion 1a is provided in the concave portion. However, the mounting portion 1a may be formed on the upper surface of the dielectric substrate 1 in a flat plate shape. Good.

Reference numeral 3 denotes a line conductor for high-frequency signal transmission formed on the upper surface of the dielectric substrate 1 from the vicinity of the mounting portion 1a to the outer periphery, and a plurality of line conductors or various directions of the dielectric substrate 1 as necessary. Formed toward. Such a line conductor 3, the dielectric substrate 1 and the ground conductor layer 2 constitute a transmission line having a microstrip line structure. Further, a coplanar line transmission line may be provided by providing ground conductors on the same plane on both sides of the line conductor 3.

Reference numeral 4 denotes a dielectric frame which is mounted on the upper surface of the dielectric substrate 1 and surrounds the mounting portion 1a and is joined with a part of the line conductor 3 interposed between the dielectric frame 4 and the dielectric substrate 1. A container of the package body is formed, and the inside is hermetically sealed by joining a lid (not shown) to the upper surface. In addition, a so-called hermetic seal portion as a signal input / output portion is formed. Note that, depending on the specifications of the high-frequency circuit package, the high-frequency circuit component 6 may be sealed with a sealing resin without using the lid.

Reference numeral 5 denotes a side wall line conductor formed continuously on the side surface of the dielectric substrate 1 with the line conductor 3, and is electrically connected to a connection conductor of an external electric circuit (not shown). The high-frequency circuit component 6 inside the package and the external electric circuit are electrically connected.

Reference numeral 6 denotes a high-frequency circuit component such as a high-frequency semiconductor element or a high-frequency circuit mounted on the mounting portion 1a, and is electrically connected to the line conductor 3 by wire bonding or ribbon bonding (not shown) or so-called bump connection. .

Reference numeral 7 denotes a side wall line conductor 5 on the lower surface of the dielectric substrate 1.
The mounting terminal conductor is formed continuously as described above, and is formed as necessary based on the specifications of the package, mainly for the purpose of improving mounting reliability. Note that, as described above, the mounting terminal conductor 7 is used.
When the terminal conductor 7 is formed, the ground conductor layer 2 is formed inside the dielectric substrate 1. However, when the mounting terminal conductor 7 is not formed, the ground conductor layer 2 is covered on the lower surface of the dielectric substrate 1. It may be formed. Also, the ground conductor layer 2 and the side wall line conductor 5
It is sufficient that electrical insulation is provided between the mounting terminal conductor 7 and a distance that does not adversely affect high-frequency characteristics.

The line conductor 3 and the mounting terminal conductor 7
The width and length are set so that the characteristic impedance Z ₀ has a desired value according to the value of the relative dielectric constant ε _r of the dielectric substrate 1. The shape of the mounting terminal conductor 7 is
The shape is not limited to the same shape as the line conductor 3 and may be various shapes suitable for mounting terminals, for example, not only metallization on the dielectric substrate 1 but also media such as leads and wires.

In the high-frequency circuit package according to the present invention, the length of the side wall line conductor 5 is set to not more than の of the wavelength of the high-frequency signal transmitted by the line conductor 3 using the high-frequency circuit component 6. It is characteristic. 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. This effect is particularly noticeable when the frequency of the high-frequency signal is
This is particularly effective when the frequency is 10 GHz or higher. In particular, for a high-frequency signal having a frequency of 30 GHz or more, the length of the side wall line conductor 5 is set to ８ of the wavelength of the high-frequency signal.
By the following, an increase in impedance can be effectively suppressed even in such a higher frequency region, and a high-frequency circuit package having good high-frequency characteristics and low reflection characteristics can be obtained.

Such a side wall line conductor 5 is usually set to a length substantially equal to the length of the side surface (the height of the side wall) of the dielectric substrate 1, but the mounting terminal conductor 7 is formed. Otherwise, it may be formed on the side surface of the dielectric substrate 1 as shorter than the length of the side surface of the dielectric substrate 1. Thereby, both the strength required for the dielectric substrate 1 and the high-frequency characteristics required for the transmission line for transmitting a high-frequency signal are ensured, and a highly reliable high-frequency circuit package can be obtained.

Next, another embodiment of the high-frequency circuit package according to the present invention will be described with reference to FIGS. 2A and 2B which are a cross-sectional view and a plan view of a main part similar to FIG.

In FIG. 2, the same parts as those in FIG. 1 are denoted by the same reference numerals, and 8 is a position at a distance of not more than half the wavelength of the high frequency signal from the side wall line conductor 5 on both sides of the line conductor 3. A ground through conductor formed from the upper surface of the dielectric substrate 1 to at least the ground conductor layer 2. As shown in FIG. 2, the ground through conductor 8 has a structure in which the ground conductor layer 2 is formed on the dielectric substrate 1.
Is formed from the ground conductor layer 2 to the upper surface of the dielectric substrate 1, but is formed on the lower surface of the dielectric substrate 1 as shown by a broken line in FIG. It may be extended to. Ground conductor layer 2 is a dielectric substrate 1
Is formed on the lower surface of the dielectric substrate 1, the ground through conductor 8 is provided to penetrate the dielectric substrate 1 from the lower surface to the upper surface.

The distance between the ground through conductor 8 and the line conductor 3 is within a range of a half or less of the wavelength of the high-frequency signal indicated by a dashed line in FIG. ,
What is necessary is just to set it to the position which does not adversely affect the high-frequency characteristics to the line conductor 3 and does not cause the characteristic impedance Z ₀ to be mismatched.

Further, a plurality of ground through conductors 8 may be formed on both sides of the line conductor 3, respectively, and the same plane grounding may be formed on both sides of the line conductor 3 on the upper surface of the dielectric substrate 1 so as to form a so-called coplanar line structure. Conductors may be provided, and these may be connected to the ground through conductor 8.

By forming such a grounding through conductor 8, it is possible to supplement a capacitance component to the high impedance side wall line conductor 5, so that impedance mismatch in the side wall line conductor of the package can be prevented. Can be. As a result, it is possible to effectively suppress the impedance mismatching in the electrical connection between the high-frequency circuit component 6 and the external electric circuit, to suppress the deterioration of the transmission characteristics of the high-frequency signal, and to reduce the reflection loss of the high-frequency circuit. Can be packaged.

The ground through conductor 8 may be formed of a through-hole conductor, a via conductor, or the like. The position of the through conductor 8 is parallel to the line conductor 3 and is spaced from the line conductor 3 by a quarter or less of the wavelength of the high-frequency signal. Just set it.

The dielectric substrate 1 in the high-frequency circuit package according to the present invention is made of, for example, a ceramic material such as alumina ceramics or aluminum nitride ceramics, an inorganic material such as glass ceramics, or PTFE.
A resin material such as (polytetrafluoroethylene), glass epoxy, or polyimide may be 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 needed, and a ground conductor layer 2, a line conductor 3, a side wall line conductor 5, It may be manufactured by printing and filling a metal paste to become the mounting terminal conductor 7 and the ground through conductor 8, laminating these green sheets up and down, and integrally firing at about 1000 ° C.

Alternatively, the ground conductor layer 2, the line conductor 3, and the side wall line conductor 5 having a predetermined pattern are formed on the upper surface, side surfaces, and lower surface of the fired dielectric substrate 1 by various thin film methods or printing and firing methods.
The mounting terminal conductor 7 may be formed, and the ground through conductor 8 may be formed.

The conductor for forming the ground conductor layer 2, the line conductor 3, the side wall line conductor 5, the mounting terminal conductor 7, and the ground through conductor 8 is tungsten, copper, nickel, gold, chrome, nichrome, tantalum nitride.・ Titanium / palladium and their alloys may be used, and their formation is
Various thin film methods, a combination of a thin film method and a photolithography method, or a printing / firing method may be used.

[0032]

EXAMPLE 1 As a high-frequency circuit package of the present invention shown in FIG. 1, a mounting portion 1a is formed on an upper surface of a dielectric substrate 1 having a grounding conductor layer 2 formed therein and having a relative dielectric constant .di- _elect cons. A dielectric frame having a line width of 150 μm, a distance of 100 μm from the ground conductor on the same plane, a dielectric substrate 1 and ε _r of 9 and a height of 300 μm from the vicinity to the front of the dielectric frame 4. A line conductor 3 having a coplanar line structure having a line width of 80 μm and an interval of 135 μm with the ground conductor on the same plane was formed between the line conductors 3 and 4. Also, a side wall line conductor 5 having a line width of 150 μm is formed on the side surface of the dielectric substrate 1.
Is continuously formed on the outer periphery of the dielectric substrate 1 with the line conductor 3,
Several different lengths were made.

Then, when the reflection characteristics for a high frequency signal of 30 GHz when the length of the side wall line conductor 5 was changed were analyzed, the results shown in FIG. 3 were obtained. FIG. 3 is a diagram showing a change in the reflection loss of the high-frequency signal with respect to the length of the side wall line conductor 5. The horizontal axis represents the length of the side wall line conductor 5, and the vertical axis represents the magnitude of the reflection loss (unit: dB). In the figure, open circles indicate analysis values, and solid lines indicate characteristic curves.

As can be seen from FIG. 3, by setting the length of the side wall line conductor 5 to λ / 4 or less, the reflection loss can be suppressed to a small value of -10 dB or less which is practical for a high-frequency circuit package. In particular, the length of the side wall line conductor 5 is set to λ / 8.
By setting the values as follows, it is understood that the reflection loss is suppressed to a very small value of less than -15 dB, and that good reflection characteristics are obtained.

Example 2 In the same high-frequency circuit package as in [Example 1], the dielectric substrate 1 having ε _r of 9.9 · 8.6 and 5.7 as the high-frequency circuit package of the present invention shown in FIG. Several grounding conductors 8 each having a diameter of 0.2 mm were formed at a distance of less than half the wavelength of the high-frequency signal from the side wall line conductors 5 on both sides of the line conductors 3. did.

Then, when a change in the characteristic impedance of the side wall line conductor 5 depending on the position of the ground through conductor 8 was analyzed, a result as shown in FIG. 4 was obtained. FIG.
Is a diagram showing the change of the characteristic impedance of the side wall line conductor 5 with respect to the distance of the ground line conductor 5 from the side wall line conductor 5, and the horizontal axis is the distance (unit: mm) of the ground line conductor 5 from the side wall line conductor 5. The vertical axis represents the characteristic impedance (unit: Ω), and the characteristic curve in the figure shows the results for the dielectric substrate 1 with ε _r of 9.9 · 8.6 and 5.7, respectively, with the dashed line, the broken line, and the solid line. Note that the distance between the side wall line conductor 5 and the ground through conductor 8 is changed between 0.4 mm and 1.0 mm, and this distance corresponds to a half or less of the transmission wavelength of a signal of about 60 GHz.

As can be seen from FIG. 4, by providing the ground through conductor 8 at a distance of one half or less of the wavelength of the high frequency signal from the side wall line conductor 5, impedance mismatch can be prevented.
In addition, higher-order modes generated in discontinuous portions could be suppressed.

Example 3 In the same high-frequency circuit package as in Example 1, by setting the thickness of the dielectric substrate 1 to 600 μm, the length of the side wall line conductor 5 was set to 4 times the wavelength of the high-frequency signal at 30 GHz. Two ground through conductors 8 were arranged at a distance of 1 mm from the end of the side wall line conductor 5. Thus, a sample A of the high-frequency circuit package of the present invention was obtained.

Further, a package was prepared by removing the two ground through conductors 8 from the sample A, thereby obtaining a conventional high frequency circuit package sample B as a comparative example.

For these samples A and B, frequency characteristics of S parameters were obtained by a three-dimensional structural analysis simulator (HFSS).

FIG. 5 shows the result. FIG. 5 is a graph showing the frequency characteristics of the S parameter. The horizontal axis represents the frequency (unit: GHz), the vertical axis represents the reflection coefficient or the transmission coefficient (unit: dB), and the solid lines in the figure represent the sample A, respectively.・ B
The characteristic curve for the S _11, dashed line sample A · respectively
Shows the characteristic curve for S ₁₂ of B.

As can be seen from FIG. 5, in the sample A, the ground through conductor 8 was provided at a distance of less than half the wavelength of the high frequency signal from the side wall line conductor 5, so that the impedance of the side wall line conductor 5 was reduced. Can prevent inconsistencies,
Good transmission characteristics were obtained as compared with Sample B.

From the above results, according to the high-frequency circuit package of the present invention, in the surface-mount type high-frequency circuit package having the side wall conductor as the surface-mount signal input / output portion on the side surface of the dielectric substrate, It was confirmed that the band also had good transmission characteristics with low reflection in the band.

It should be noted that the present invention is not limited to the above examples, and various changes and improvements can be made without departing from the spirit of the present invention.

[0045]

According to the high-frequency circuit package of the present invention, in a surface-mount type high-frequency circuit package having a side-wall line conductor as a surface-mounting signal input / output portion on the side surface of the dielectric substrate, Since the length is less than one-fourth of the wavelength of the high-frequency signal transmitted by the line conductor using the high-frequency circuit component, the side-wall line conductor reduces the capacitance component and the inductance component that are problematic in the high-frequency characteristics. The increase does not occur, and as a result, it is possible to suppress the transmission line from becoming high impedance, increasing the reflection of the high-frequency signal and reducing the transmission characteristics of the high-frequency signal.

Further, in the case where the ground through conductor is formed from the upper surface of the dielectric substrate to at least the ground conductor layer at a distance of not more than half the wavelength of the high frequency signal from the side wall conductor on both sides of the line conductor. In addition, it is possible to prevent the impedance mismatch in the side wall conductor of the package, effectively suppress the impedance mismatch in the electrical connection between the high-frequency circuit component and the external electric circuit, and reduce the deterioration of the transmission characteristic of the high-frequency signal. Thus, a high-frequency circuit package with low reflection loss can be obtained.

Further, when the mounting terminal conductor is formed continuously on the lower surface of the dielectric substrate and the side wall line conductor, the connection strength to the external electric circuit can be increased, and the mounting reliability can be improved.

As described above, according to the present invention, in a surface mount type high frequency circuit package having side wall conductors as signal input / output portions for surface mount on the side surfaces of a dielectric substrate, a low level against a high frequency signal is obtained. It was possible to provide a high-frequency circuit package having reflection characteristics and good transmission characteristics.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are a cross-sectional view and a plan view, respectively, showing an example of an embodiment of a high-frequency circuit package according to the present invention.

FIGS. 2 (a) and 2 (b) are a cross-sectional view and a plan view, respectively, showing another example of a high-frequency circuit package according to another embodiment of the present invention.

FIG. 3 is a diagram showing a change in reflection loss of a high-frequency signal with respect to the length of a side wall line conductor in the high-frequency circuit package of the present invention.

FIG. 4 is a diagram showing a change in characteristic impedance of a side wall line conductor with respect to a position of a ground through conductor in a high-frequency circuit package of the present invention.

FIG. 5 is a diagram showing frequency characteristics of S parameters in a high-frequency circuit package.

[Description of Signs] 1 ... Dielectric substrate 1a ... Mounting part 2 ... Ground conductor layer 3 ... Line conductor 4 ... Dielectric frame 5 ... ····· Side-wall line conductor 6 ···· High-frequency circuit components 7 ···· Terminal conductor for mounting 8 ···· Ground-through conductor

Claims (3)

[Claims] A dielectric substrate having a ground conductor layer formed on a lower surface or inside thereof, a mounting portion for mounting a high-frequency circuit component on an upper surface, and a line conductor extending from the vicinity of the mounting portion to the outer periphery; A dielectric frame body surrounding the mounting portion on the upper surface of the substrate and joined with a part of the line conductor sandwiched therebetween, and a side wall line conductor formed continuously with the line conductor on a side surface of the dielectric substrate. The side wall line conductor has a length that is equal to or less than a quarter of the wavelength of a high frequency signal transmitted by the line conductor. 2. A ground through conductor extending from the upper surface of the dielectric substrate to at least the ground conductor layer at a distance of not more than half the wavelength of the high frequency signal from the side wall line conductor on both sides of the line conductor. The high frequency circuit package according to claim 1, wherein the package is formed. 3. The high-frequency circuit package according to claim 1, wherein a mounting terminal conductor is formed continuously with the side wall line conductor on a lower surface of the dielectric substrate.