JP2000040771A - High frequency package - Google Patents

Abstract

(57) [Problem] To provide a high-frequency package capable of obtaining good high-frequency transmission characteristics. SOLUTION: By forming a high-frequency signal line 2 by a microstrip circuit, mode mismatch at a connection portion between a high-frequency semiconductor element 6 and a high-frequency signal line 2 is prevented. Further, by forming the control signal line 3 by a coplanar line, the coupling between the high-frequency signal line 2 and the control signal line 3 is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency package for mounting a semiconductor device operating in a high-speed or high-frequency band.

[0002]

2. Description of the Related Art In recent years, personalization and wireless communication of information have been advanced, and radio waves used for wireless communication have already been used up to a microwave region having a frequency band of 1 to 30 GHz. Further, utilization of a millimeter wave region having a frequency band of 30 to 300 GHz has been studied in the future, and many semiconductor devices operating at 30 GHz or higher have appeared. For this reason,
There is also a demand for a high-frequency package on which a high-frequency semiconductor element is mounted to maximize the performance of the high-frequency semiconductor element.

However, when a signal of several tens of GHz or more propagates, a high-frequency wiring pattern that need not be taken into consideration in a conventional package and a control wiring pattern through which a relatively low-frequency signal propagates have an electromagnetic field. The occurrence of coupling causes a problem in that the transmission characteristics of the high-frequency signal line are degraded or malfunctions occur. In order to avoid such an effect, the conventional high-frequency package is arranged by increasing the distance between the high-frequency signal wiring pattern and the control wiring pattern for supplying a bias or control signal, or by separating them. Although the occurrence of coupling was prevented, it was impossible to completely prevent the occurrence of coupling. In recent years, the size of the package has also been required to be reduced in size, and it is difficult to increase the distance between the high-frequency signal wiring pattern and the control wiring pattern more than ever. Therefore, Japanese Patent Laid-Open No.
As disclosed in Japanese Patent No. 36702, a high-frequency package in which a high-frequency wiring pattern is formed of a coplanar line has been proposed.

According to the high-frequency package disclosed in Japanese Patent Application Laid-Open No. 4-336702, the high-frequency signal wiring pattern is constituted by a coplanar line, so that the high-frequency signal wiring pattern and the control wiring pattern generate coupling. Trying to prevent.

[0005]

However, when a high-frequency signal wiring pattern is formed by a coplanar line, if there is no ground terminal on both sides of a high-frequency signal pad of a high-frequency semiconductor element to be connected, the high-frequency signal wiring pattern is formed by a coplanar line. Due to mode mismatch at the connection between the high-frequency signal line and the high-frequency signal pad in the high-frequency semiconductor element,
There is a problem that the transmission characteristics of the high-frequency signal line deteriorate.

Further, if ground pads are formed on both sides of the high-frequency signal pad of the high-frequency semiconductor element as a measure for preventing the transmission characteristics of the high-frequency signal line from deteriorating, the size of the semiconductor element itself increases. was there.

An object of the present invention is to provide a high-frequency package that suppresses deterioration of high-frequency transmission characteristics. Another object of the present invention is to provide a high-frequency semiconductor device and a high-frequency package capable of reducing the mounting area by reducing the size of the package.

[0008]

According to the high-frequency package according to the first aspect of the present invention, the high-frequency signal transmission wiring pattern is formed of a microstrip line, thereby connecting the high-frequency component and the high-frequency signal transmission wiring. This prevents the occurrence of mode inconsistency. Furthermore, by forming the control wiring pattern as a coplanar line or a grounded coplanar line, the coupling between the high-frequency signal transmission wiring and the control wiring is eliminated, thereby generating unnecessary high-frequency components from the high-frequency signal transmission wiring. However, unnecessary high frequency components are prevented from entering the control wiring. Therefore, it is possible to prevent the occurrence of mode mismatch at the connection portion between the high-frequency component and the high-frequency signal transmission wiring, and to eliminate unnecessary coupling between the high-frequency signal transmission wiring and the control wiring, thereby achieving good transmission. A high-frequency package having characteristics can be obtained.

According to the high-frequency package according to the second aspect of the present invention, the internal high-frequency signal transmission line and the external high-frequency signal transmission line are electrically connected by via holes, and the internal control signal transmission line and the external control signal transmission line are connected to each other. Are electrically connected to the via holes, the external high-frequency signal transmission line and the external control signal transmission line can be arranged on the surface of the high-frequency package opposite to the surface on which the high-frequency components are mounted. Therefore, when the mounting end of each signal transmission line and the high-frequency component are arranged on the same plane, the high-frequency package can be mounted on the same plane as the surface of the mounting board without processing the mounting board. Thus, the high-frequency package can be easily mounted. Further, when a sealing cap is attached to the high-frequency component, the cap does not touch the wiring of the high-frequency package, so that the cap can be easily attached.

According to the high-frequency package according to the third aspect of the present invention, the high-frequency package can be easily attached to the mounting board by attaching the metal leads. According to the high frequency package of the present invention, the mounting area of the high frequency package can be reduced by installing the solder balls.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; (First Embodiment) FIGS. 1 and 2 show a high-frequency package according to a first embodiment of the present invention. As shown in FIG. 1, a concave portion is provided in the center of a dielectric substrate 1 as a package substrate, and a mounting portion 7 for a high-frequency component such as a semiconductor device 6 is formed. Is done. On the surface of the dielectric substrate 1, a ground pattern 5, a high-frequency signal line 2 having a predetermined line width, and a control signal line 3 having a predetermined line width and a predetermined distance from the ground pattern 5 are formed. ing. A ground pattern 5 is formed on the back surface of the dielectric substrate 1 as shown in FIG. Further, a via hole 8 is formed to electrically connect the ground pattern 5 on the front surface and the back surface. A microstrip line is formed as a high-frequency signal transmission line by the ground pattern 5 and the high-frequency signal line 2 on the back surface. Further, a coplanar line is formed as a control signal transmission line by the ground pattern 5 and the control signal line 3 on the front and rear surfaces. Semiconductor element 6 of high-frequency signal line 2
Is connected to the high-frequency signal pad 9 of the semiconductor element 6 by a wire 4 and the like, and the control signal line 3 is connected to the control signal pad of the semiconductor element 6 by a wire 4 and the like. Is done. The semiconductor element 6 is sealed with a resin or metal cap (not shown).

In the microstrip line forming the high-frequency signal line 2 of the high-frequency package according to the first embodiment, the line width is reduced in order to prevent occurrence of high-frequency mode mismatch at a connection portion such as the wire 4. 100-200
The deterioration of the high-frequency transmission characteristics is suppressed by setting the line height to 10 to 15 μm and the thickness of the dielectric substrate 1 to 250 μm.

Further, when the line width is reduced as described above, it is necessary to bring the ground conductor constituting the microstrip line as the high-frequency signal line 2 close to the center conductor. For this reason, in the first embodiment, the dielectric substrate 1 and the ground conductor are laminated, and the ground conductor is sandwiched between the dielectric substrates 1 so that the ground conductor and the center conductor are brought close to each other. Maintains impedance characteristics. Further, by disposing a ground conductor in the middle of the dielectric substrate 1,
The strength of the high-frequency package itself can be improved.

FIG. 11 shows a conventional high-frequency package as a comparative example of the high-frequency package of the first embodiment shown in FIG. In FIG. 11, the same components as those in the first embodiment shown in FIG. In the conventional high-frequency package, by forming the high-frequency signal line 2 by a coplanar line, the occurrence of coupling between the high-frequency signal line 2 and the control signal line is prevented.

FIG. 10 shows the transmission characteristics of the high-frequency signal line in the conventional high-frequency package and the transmission characteristics of the high-frequency signal line in the high-frequency package of the first embodiment.
In both high-frequency packages, the dielectric substrate 2 is made of alumina, and the high-frequency signal line 2, the control signal line 3, the ground pattern 5, and the via hole 8 are made of tungsten.
Gold plating was applied to the wiring and ground pattern on the front and back surfaces. As is clear from FIG. 10, the conventional high-frequency package shows degradation in transmission characteristics due to mode mismatch around 43 GHz. However, in the first embodiment according to the present invention, this degradation in transmission characteristics is not seen even at 43 GHz or higher. Although not shown, good transmission characteristics could be obtained up to 50 GHz.

(Second Embodiment) FIGS. 3, 4 and 5 show a high-frequency package according to a second embodiment of the present invention. Components substantially the same as those in the first embodiment are denoted by the same reference numerals.
As shown in FIG. 3, on the surface of the dielectric substrate 1, a ground pattern 5, an inner high-frequency signal line 11 having a predetermined line width, and an inner line having a predetermined line width and a predetermined distance from the ground pattern 5 are provided. A control signal line 12 is formed. As shown in FIG. 4, a ground pattern 5 and an inner control signal line 12 having a predetermined interval are formed on the back surface of the dielectric substrate.

Further, as shown in FIG. 5, the inner high-frequency signal line 11 and the outer high-frequency signal line 13, the inner control signal line 12 and the outer control signal line 14, and the front and back ground patterns 5 are respectively formed. They are electrically connected by via holes 8. The semiconductor element 6 is sealed by a sealing cap 15. The inner high-frequency signal line 11 on the front surface and the ground pattern 5 on the rear surface and the outer high-frequency signal line 13 on the rear surface and the ground pattern 5 on the front surface form a microstrip line as a high-frequency signal transmission line, respectively. A coplanar line is formed as a control signal transmission line by the control pattern 5 and the inner control signal line 12, the ground pattern 5 on the front and back surfaces, and the outer control signal line 14.

In the microstrip line forming the high-frequency signal line of the high-frequency package of the second embodiment, the occurrence of high-frequency mode mismatch at the connection portion such as the wire 4 is prevented as in the first embodiment. Therefore, the deterioration of the high-frequency transmission characteristics is suppressed by setting the line width to 100 to 200 μm, the line height to 10 to 15 μm, and the thickness of the dielectric substrate 1 to 250 μm.

Also, in the second embodiment, as in the first embodiment, the dielectric substrate 1 and the ground conductor are laminated, and the ground conductor is disposed in the middle of the dielectric substrate 1 so as to sandwich the ground conductor. The conductor and the center conductor are brought close to each other to maintain impedance characteristics. Further, by disposing a ground conductor in the middle of the dielectric substrate 1, the strength of the high-frequency package itself is improved.

Next, the operation of the high-frequency package having the above configuration will be described with reference to FIGS. The high-frequency signal input to the outer high-frequency signal line 13 is transmitted to the inner high-frequency signal line 11 through the via hole 8 as a microstrip propagation mode. Further, this high-frequency signal is transmitted to the high-frequency signal pad 9 of the semiconductor element 6 such as GaAs or Si via the wire 4, and the semiconductor element 6 receives an external high-frequency signal. At this time, the high-frequency signal transmitted in the microstrip propagation mode is propagated without causing mode mismatch at the connection between the semiconductor element 6 and the inner high-frequency signal line 11.

(Third Embodiment) FIGS. 6 and 7 show a high-frequency package according to a third embodiment of the present invention. Components substantially the same as those of the second embodiment are denoted by the same reference numerals. In the third embodiment, external leads 16 as metal leads for mounting are provided at the ends of the outer high-frequency signal line 13 and the outer control signal line 14, thereby facilitating mounting on a mounting board.

(Fourth Embodiment) FIGS. 8 and 9 show a high-frequency package according to a fourth embodiment of the present invention. Components substantially the same as those of the second embodiment are denoted by the same reference numerals. In the fourth embodiment, solder balls as metal balls for mounting are provided at the ends of the outer high-frequency signal line 13 and the outer control signal line 14, so that the mounting area of the high-frequency package can be reduced.

Although a plurality of high-frequency signal lines are provided for each side of the dielectric substrate in the above embodiments, two or more pairs of high-frequency signal lines are provided corresponding to the multi-terminal semiconductor element. The same effect can be obtained as the arrangement structure.

In the above embodiments, three pairs of control signal lines are provided for each side, but the present invention is not limited to this. Further, in the above embodiments, the via holes are used to electrically connect the ground pattern on the front surface and the back surface of the dielectric substrate. However, the same effect can be obtained by connecting using the through holes. Can be. In addition, although alumina was used for the dielectric substrate in the above embodiments, the same effect can be obtained by using another ceramic material or resin-based material as the dielectric substrate,
The wiring, via holes, through holes, and ground patterns are not limited to tungsten, and similar effects can be obtained with metals such as Cu, Au, Ag, and Al and other conductive materials. Further, in the above-described embodiments, the semiconductor element and the high-frequency package are connected by wires, but they may be connected by solder bumps, and the connection is not limited to wires.

As described above, according to the high-frequency package of the present invention, since the high-frequency signal line is constituted by the microstrip line, a good mode mismatch does not occur at the connection between the high-frequency package and the semiconductor element. Transmission characteristics can be obtained. Further, by configuring the control signal line with a coplanar line, unnecessary electromagnetic coupling with the high-frequency signal line can be prevented. Therefore, a good high-frequency device can be obtained as a whole.

Further, by adopting the form of the present invention, it is not necessary to form ground pads on both sides of the signal pad on the semiconductor element side, so that the semiconductor element itself can be downsized, and further downsized. The whole high-frequency package including the miniaturized semiconductor element can be reduced in size.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing a configuration of a high-frequency package according to a first embodiment of the present invention.

FIG. 2 is a bottom view schematically showing the configuration of the high-frequency package according to the first embodiment of the present invention.

FIG. 3 is a plan view schematically showing a configuration of a high-frequency package according to a second embodiment of the present invention.

FIG. 4 is a bottom view schematically showing a configuration of a high-frequency package according to a second embodiment of the present invention.

FIG. 5 is a sectional view of the high-frequency package according to the second embodiment of the present invention, taken along line VV of FIG. 3;

FIG. 6 is a bottom view schematically showing a configuration of a high-frequency package according to a third embodiment of the present invention.

FIG. 7 is a cross-sectional view of a high-frequency package according to a third embodiment of the present invention, taken along line VII-VII of FIG.

FIG. 8 is a bottom view schematically showing a configuration of a high-frequency package according to a fourth embodiment of the present invention.

FIG. 9 is a cross-sectional view of a high-frequency package according to a fourth embodiment of the present invention, taken along line IX-IX of FIG.

FIG. 10 is a graph showing transmission characteristics of a high-frequency signal line between a conventional high-frequency package and a high-frequency package according to an embodiment of the present invention.

FIG. 11 is a plan view schematically showing a configuration of a conventional high-frequency package.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 dielectric substrate (package substrate) 2 high-frequency signal line (high-frequency signal transmission wiring pattern) 3 control signal line (control wiring pattern) 4 wire 5 ground pattern 6 semiconductor element (high-frequency component) 7 mounting part 8 Via hole 9 High-frequency signal pad 10 Control signal pad 11 Inner high-frequency signal line (internal high-frequency signal line) 12 Inner control signal line (internal control signal line) 13 Outer high-frequency signal line (external high-frequency signal line) 14 outside control signal line (external control signal line) 15 sealing cap 16 external lead (metal lead) 17 solder ball (metal ball)

Claims (4)

[Claims] 1. A high-frequency component is disposed on a package substrate, a high-frequency signal transmission wiring pattern for transmitting a high-frequency signal input to or output from the high-frequency component, and a bias or control signal applied to the high-frequency component. A control wiring pattern for transmitting a low-frequency signal for supplying, the high-frequency signal transmission wiring pattern is configured by a microstrip line, and the control wiring pattern is configured by a coplanar line or a grounded coplanar line. A high frequency package characterized by the following. 2. A package substrate on which a high-frequency component is disposed, an internal high-frequency signal transmission line formed on a cavity side of the package substrate on which the high-frequency component is disposed, and an external high-frequency signal transmission line formed on an external mounting side A high-frequency signal transmission wiring pattern for transmitting a high-frequency signal input to or output from the high-frequency component, an internal control signal transmission line formed on the cavity side, and formed on the external mounting side A control wiring pattern for transmitting a low-frequency signal for supplying a bias or control signal to the high-frequency component, and the high-frequency signal transmission wiring pattern is a microstrip line. Wherein the control wiring pattern is a coplanar line or a grounded coplanar line. The internal high-frequency signal transmission line and the external high-frequency signal transmission line are electrically connected by a via hole, and the internal control signal transmission line and the external control signal transmission line are electrically connected by a via hole. Features high frequency package. 3. An end of the external high-frequency signal transmission line,
The high-frequency package according to claim 2, wherein metal leads are provided at both ends of the external control signal transmission line. 4. An end of the external high-frequency signal transmission line,
The high-frequency package according to claim 2, wherein metal balls are provided at both ends of the external control signal transmission line.