JP2000164755A - 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 for high-frequency signals. SOLUTION: A high-frequency circuit package comprises a dielectric board 1, equipped with a ground conductor layer 2 formed inside and a mounting region 1a which is located on its upside and where a high-frequency circuit part 9 is mounted, a dielectric frame 3 jointed to the top surface of the dielectric board 1 surrounding the mount region 1a, a line conductor 4 formed on the underside of the dielectric board 1 corresponding to the dielectric frame 3 and extending to the periphery, a sidewall line conductor 5 formed on the side of the dielectric board 1 extending continuously from the line conductor 4, and a through-conductor 6 which is formed extending from the other end of the line conductor 4 inside the dielectric frame 3 to the top surface of the board 1, 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 prevented from increasing in impedance or protected against impedance mismatching, reduced in reflection properties, and satisfactory in transmission properties.

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 line conductor changes from the microstrip mode to the strip mode at the hermetic seal portion sandwiched between the dielectric frame and the dielectric substrate. Since the switching is performed, there is a problem that impedance mismatch occurs in this portion, the reflection loss increases, and the high-frequency characteristics of the transmission line deteriorate.

In a transmission line composed of a line conductor and a side wall line conductor, the presence of the side wall line conductor causes a decrease in capacitance component and an increase in inductance component.
For this reason, the transmission line has a high impedance, so that the reflection of the high-frequency signal increases, and the transmission characteristics of the high-frequency signal deteriorate. 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 the high-frequency signal are greatly reduced.

SUMMARY OF THE INVENTION The present invention has been devised in view of the above-mentioned problems of the prior art, and has as its object to provide a surface mount type having side wall conductors as signal input / output portions for surface mount on the side surfaces 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.

[0008]

According to the present invention, there is provided a high-frequency circuit package comprising a dielectric substrate having a ground conductor layer formed therein and a mounting portion for mounting a high-frequency circuit component formed on an upper surface thereof; A dielectric frame joined to the upper surface of the mounting portion so as to surround the mounting portion, and formed on the lower surface of the dielectric substrate;
A line conductor extending from a position corresponding to the inside of the dielectric frame to the outer periphery, a side wall line conductor formed continuously with the line conductor on a side surface of the dielectric substrate, and the other end of the line conductor. A penetrating conductor formed on the upper surface of the dielectric substrate inside the dielectric frame, wherein the length of the side wall line conductor is one quarter of the wavelength of a high frequency signal transmitted by the line conductor. It is characterized by the following.

In the above structure, the high-frequency circuit package according to the present invention may be arranged such that the ground conductor layer is located 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. A ground through conductor extending from an upper surface to a lower surface of the dielectric substrate electrically connected to the dielectric substrate is formed.

According to 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 near the mounting portion inside the dielectric frame, and the through-conductor is connected to the dielectric substrate. Since the external electric circuit is connected to the side wall line conductor connected via the line conductor formed on the lower surface of the device, the mode is switched from the microstrip mode to the strip mode like a conventional line conductor passing through a hermetic seal portion. Therefore, there is no occurrence of impedance mismatching, no increase in reflection loss, and no deterioration in high-frequency characteristics of the transmission line.

Further, since the length of the side wall line conductor is one-fourth or less of the wavelength of the high-frequency signal transmitted by the line conductor using a high-frequency circuit component, the loss due to the length of the transmission line is minimized. It is possible to limit to
This 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. Therefore, the transmission line has a high impedance and the reflection of high frequency signals increases, so that the transmission characteristics of high frequency signals Does not decrease.

In addition, 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, the lower surface of the dielectric substrate and at least the ground conductor layer are electrically connected to the ground conductor layer. When a grounded through conductor extending from the upper surface to the lower surface of the dielectric substrate is formed, an appropriate capacitance component can be provided between the line conductor and the grounded through conductor. Can be prevented.

[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.

Reference numeral 3 denotes a dielectric frame joined to the upper surface of the dielectric substrate 1 so as to surround the mounting portion 1a. The dielectric frame 3 and the dielectric substrate 1 constitute a package body container.

Then, a lid (not shown) is joined to the upper surface to hermetically seal the inside. Further, depending on the specification of the high-frequency circuit package, the high-frequency circuit component 8 may be sealed with a sealing resin without using the lid.

Reference numeral 4 denotes a line conductor for high-frequency signal transmission formed on the lower surface of the dielectric substrate 1 so as to extend from a position corresponding to the vicinity of the mounting portion 1a inside the dielectric frame 3 to the outer periphery. Formed in various directions of the dielectric substrate 1. Such a line conductor 4, the dielectric substrate 1 and the ground conductor layer 2 constitute a transmission line having a microstrip line structure. Note that this line conductor 4 is
A coplanar line transmission line may be provided by providing the same plane ground conductor on both sides.

Reference numeral 5 denotes a side wall line conductor formed continuously on the side surface of the dielectric substrate 1 with the line conductor 4, and is electrically connected to a connection conductor of an external electric circuit (not shown). The high-frequency circuit component 8 inside the package and the external electric circuit are electrically connected. It is sufficient that electrical insulation is ensured between the ground conductor layer 2 and the side wall line conductor 5 and a distance that does not adversely affect high frequency characteristics is provided.

Reference numeral 6 denotes the other end of the line conductor 4, that is, from the end on the side corresponding to the vicinity of the mounting portion 1a inside the dielectric frame 3, to the vicinity of the mounting portion 1a inside the dielectric frame 3. A high-frequency circuit component 8 is electrically connected to the through conductor 6 via the electrode pad 7 or directly at the upper end thereof. Incidentally, the line conductor 4 and the through conductor 6, respectively in accordance with the value of the relative dielectric constant epsilon _r of the dielectric substrate 1, the characteristic impedance Z ₀ of the desired width, diameter and length so that the value is set You.

Reference numeral 8 denotes a high-frequency circuit component such as a high-frequency semiconductor device or a high-frequency circuit mounted on the mounting portion 1a. The electrode pad 7 or the through conductor 6 is electrically connected to the electrode pad 7 or the through conductor 6 by wire bonding or ribbon bonding (not shown) or so-called bump connection. Connected.

In the high-frequency circuit package of the present invention, the length of the side wall line conductor 5 is set to not more than ４ of the wavelength of the high-frequency signal transmitted by the line conductor 4 using the high-frequency circuit component 8. . 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. Among them, the frequency is 30
For a high-frequency signal of GHz or higher, the length of the side wall line conductor 5 is set to 1/8 or less of the wavelength of the high-frequency signal, thereby effectively suppressing an increase in impedance even in such a higher frequency region. Thus, a high-frequency circuit package having low reflection characteristics and good high-frequency 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 of the dielectric substrate 1 (height of the side wall). It may be formed on the side surface of the dielectric substrate 1 as shorter than the length. 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 9 is a through conductor 6 on both sides of the line conductor 4.
At a distance less than half the wavelength of the high-frequency signal from
The ground through conductor extends from the upper surface to the lower surface of the dielectric substrate 1 electrically connected to the ground conductor layer 2. The distance between the ground through conductor 9 and the line conductor 4 is different from the through conductor 6 in FIG.
(B) A half of the wavelength of the high-frequency signal indicated by a dashed line in FIG.
What is necessary is just to set it within the range of the following distances.

Further, a plurality of ground through conductors 9 may be formed on both sides of the line conductor 4 on the both sides of the line conductor 4. On the lower surface of the dielectric substrate 1, both sides of the line conductor 4 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 9.

By forming such a grounded through conductor 9, it is possible to supplement a capacitive component with respect to the high impedance through conductor 6, so that impedance mismatch in the through conductor 6 can be prevented. as a result,
Impedance mismatch in the electrical connection between the high-frequency circuit component 8 and the external electric circuit can be effectively suppressed to suppress the deterioration of the transmission characteristics of the high-frequency signal. be able to. This ground through conductor 9 may be formed of a through-hole conductor, a via conductor, or the like.

The dielectric substrate 1 in the high-frequency circuit package of the present invention is made of 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 glass ceramics, a concave portion or a through hole serving as a through conductor is formed in a green sheet of glass ceramics as necessary, and a ground conductor layer 2, a line conductor 4, a side wall line conductor 5, Through conductor 6 / Ground through conductor 9
The green paste is printed and applied, and these green sheets are stacked one on top of the other and fired integrally at about 1000 ° C.

Alternatively, the ground conductor layer 2, the line conductor 4, 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 through conductor 6 may be formed and the ground through conductor 9 may be formed.

The conductor for forming the ground conductor layer 2, the line conductor 4, the side wall line conductor 5, the through conductor 6, and the ground through conductor 9 may be tungsten, copper, nickel, gold, chrome, nichrome, tantalum nitride, or titanium. -Palladium and alloys thereof may be used, and the formation may be performed by various thin film methods, a combination of a thin film method and a photolithography method, or a printing and firing method.

[0030]

As EXAMPLES EXAMPLE 1 a high-frequency circuit package of the present invention shown in FIG. 1, the lower surface of the dielectric substrate 1 of dielectric constant to form a ground conductor layer 2 inside epsilon _r is 9, the dielectric frame From the position corresponding to the vicinity of the mounting portion 1a inside the body 3, the dielectric substrate 1
A line conductor 4 having a coplanar line structure having a line width reaching the outer periphery of 150 μm and an interval of 100 μm from a ground conductor on the same plane was formed. The line width is 150 μm on the side surface of the dielectric substrate 1.
A number of m side wall line conductors 5 having different lengths were manufactured continuously with the line conductors 4 on the outer periphery of the dielectric substrate 1. Further, a through conductor 6 having a diameter of 0.2 mm was formed from the other end of the line conductor 4 to the upper surface of the dielectric substrate 1 at a position corresponding to the vicinity of the mounting portion 1a inside the dielectric frame 3.

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. The through conductors 6 on both sides of the line conductor 4
At a distance less than half the wavelength of the high-frequency signal from
Several pieces were formed by changing the position of the ground through conductor 9 having a diameter of 0.2 mm.

Then, when a change in the characteristic impedance of the through conductor 6 depending on the position of the ground through conductor 9 was analyzed, a result as shown in FIG. 4 was obtained. FIG. 4 is a diagram showing a change in the characteristic impedance of the through conductor 6 with respect to the distance of the ground through conductor 9 from the through conductor 6. The horizontal axis represents the distance (unit: m) of the ground through conductor 9 from the through conductor 6.
m), the vertical axis represents 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, indicated by a dashed line, a broken line, and a solid line. I have. The distance between the penetrating conductor 6 and the ground terminal conductor 9 is changed between 0.4 mm and 1.0 mm, and this distance corresponds to a half or less of a signal transmission wavelength of about 60 GHz.

As can be seen from FIG. 4, by providing the ground through conductor 9 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, a higher-order mode generated in a discontinuous portion could be suppressed.

[Example 3] In the same high-frequency signal package as in [Example 1], by setting the thickness of the dielectric substrate 1 to 400 μm, the length of the side wall line conductor 5 is set to 8 of the wavelength of the high-frequency signal at 30 GHz. Less than 1 /
By arranging the two ground through conductors 9 at a distance of 1 mm from the end of, a sample A of the high-frequency circuit package of the present invention was obtained.

A sample B of a conventional high-frequency circuit package as a comparative example was obtained by removing the two ground through conductors 9 in the sample A.

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

FIG. 5 shows the result. Figure 5 is a graph showing frequency characteristics of S parameters, the horizontal axis represents the frequency (unit: GHz) and the vertical axis the reflection coefficient (unit: dB) represents the solid line in the figure for S ₁₁ of the sample A The characteristic curve of
The broken line shows a characteristic curve for S ₁₁ of sample B.

As can be seen from FIG. 5, in the sample A, since the ground through conductor 9 is provided at a distance of one half or less of the wavelength of the high frequency signal from the through conductor 6, it is possible to prevent the impedance of the through conductor 6 from being mismatched. The transmission characteristics were better than those of the sample B.

According to the above results, according to the high-frequency circuit package of the present invention, the high-frequency circuit package of the surface-mount type having the side wall conductor as the signal input / output section for the surface mount on the side surface of the dielectric substrate has a high frequency. 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 scope of the present invention.

[0043]

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 signal input / output unit for surface mounting on the side surface of a dielectric substrate, the upper end is made of a dielectric material. A high-frequency circuit component is electrically connected to a through conductor located in the vicinity of the mounting portion inside the frame, and from the through conductor to a side wall line conductor connected via a line conductor formed on the lower surface of the dielectric substrate. Since the external electric circuit is connected, impedance mismatch does not occur unlike the conventional line conductor that passes through the hermetic seal, and the return loss increases and the high-frequency characteristics of the transmission line deteriorate. There is no.

Further, since the length of the side wall line conductor is less than ４ of the wavelength of the high frequency signal transmitted by the line conductor using a high frequency circuit component, the side wall line conductor has a high frequency characteristic. The problem of a decrease in the capacitance component and an increase in the inductance component, which are problematic, does not occur. Therefore, the transmission line does not have a high impedance, so that the reflection of the high-frequency signal increases and the transmission characteristic of the high-frequency signal does not deteriorate.

Further, at a position which is less than half the wavelength of the high frequency signal from the through conductors on both sides of the line conductor, the lower surface of the dielectric substrate and at least the ground conductor layer are electrically connected to the ground conductor layer. When the ground through conductor is formed from the upper surface to the lower surface of the dielectric substrate, impedance mismatch in the through conductor can be prevented.

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, low reflection characteristics for high frequency signals are obtained. A high-frequency circuit package having good transmission characteristics having the above characteristics can be provided.

[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 through conductor with respect to a position of a ground through conductor in the high-frequency signal package of the present invention.

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

[Explanation of symbols]

 1 Dielectric substrate 1a Mounting part 2 Ground conductor layer 3 Dielectric frame 4 Line conductor 5 Side wall Line conductor 6 ... Through conductor 8 ... High frequency circuit component 9 ... Ground through conductor

Claims (2)

[Claims] A dielectric substrate having a ground conductor layer formed therein and a mounting portion for mounting a high-frequency circuit component formed on an upper surface thereof, and a dielectric bonded to the upper surface of the dielectric substrate so as to surround the mounting portion. A body frame, a line conductor formed on the lower surface of the dielectric substrate and extending from a position corresponding to the inside of the dielectric frame to the outer periphery, and formed continuously with the line conductor on a side surface of the dielectric substrate. And a through conductor formed from the other end of the line conductor to the upper surface of the dielectric substrate inside the dielectric frame, and the length of the sidewall line conductor is A high-frequency circuit package, wherein the wavelength of the high-frequency signal transmitted by the line conductor is one-fourth or less. 2. A position at a distance equal to or less than half the wavelength of the high-frequency signal from the through conductor on both sides of the line conductor,
2. The high frequency circuit package according to claim 1, wherein a ground through conductor extending from an upper surface to a lower surface of said dielectric substrate electrically connected to said ground conductor layer is formed.