JP2012231292A - Microwave package - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a microwave package which accommodates a semiconductor switch and a termination resistor as one body within a package.SOLUTION: When a semiconductor switch 7 is an ON state on the termination side, a microwave signal fed into an input end 7a of the semiconductor switch 7 is led from a termination output end 7c to a pseudo-waveguide 5 through a microstrip line 3 and a pseudo-coaxial line 4. The microwave signal led into the pseudo-waveguide 5 is converted to heat at a film resistor 1 which is disposed on a metal pattern composing the undersurface before being terminated there. Because the film resistor 1 is placed at a position close to a metal plate which constitutes a heat radiation surface, and because its breadth can be made to be the same as that of the pseudo-waveguide 5, its ability to tolerate electric power is increased.

Description

  The present invention relates to a microwave package used in a microwave transmission / reception module.

  Since the microwave transmission / reception module is configured to switch between the transmission system block and the reception system block, a high-power transmission signal may leak into the reception system during transmission. If such leakage occurs, the low noise amplifier in the receiving block is damaged or burnt out.

  For this reason, in microwave transmission / reception modules, a high-power microwave switch (hereinafter referred to as “semiconductor switch”) is conventionally used to prevent a low-noise amplifier from being damaged or burned by a leaked high-power transmission signal. Is employed in front of a low-noise amplifier, and a circuit system is employed in which a transmission signal input to a reception system is guided to a termination resistor by a semiconductor switch during transmission.

  As a configuration method of the termination resistor, for example, Patent Document 1 proposes a configuration in which an open-ended stub and a matching circuit are provided on a film resistor configured on a substrate for miniaturization. Further, Patent Document 2 proposes a configuration in which a connection portion between a film resistor and a conductor pattern formed on a substrate is connected in a taper shape in order to widen the band.

  However, these proposed termination resistors are assumed to be mounted on a material with good heat dissipation. However, the multilayer substrate constituting the microwave package storing the microwave device generally has poor heat dissipation.

Japanese Patent Laid-Open No. 7-7307 JP-A-2005-260545

  Therefore, conventionally, the semiconductor switch is mounted on the multilayer substrate as one of the microwave devices, but the termination resistor cannot be loaded in the microwave package for storing the semiconductor switch in order to improve heat dissipation, It is configured to be externally attached to the microwave package.

  Therefore, with the conventional configuration, it has been difficult to reduce the number of parts and downsize the package. In addition, the transfer characteristic is lowered at the connection between the semiconductor switch and the external termination resistor.

  The present invention has been made in view of the above, and an object thereof is to obtain a microwave package in which a semiconductor switch and a termination resistor are integrally housed in a package.

  In order to solve the above-described problems and achieve the object, the present invention provides a multilayer substrate that outputs a microwave signal input to an input terminal to one of a termination-side output terminal and a low-noise amplifier-side output terminal. A microwave package in which a semiconductor switch controlled so as to switch output to one end is mounted as one of microwave devices, and a metal pattern formed on an upper surface of an uppermost layer and a lowermost layer in the multilayer substrate A pseudo that uses a via or through hole connecting to a metal pattern formed on the lower surface as a central conductor, and an interlayer via or interlayer through hole arranged in an annular shape by connecting two or more layers around it as an outer conductor. A coaxial line, a microstrip line that connects a terminal-side output end of the semiconductor switch and a central conductor of the pseudo-coaxial line, and an interlayer via or interlayer that connects two or more layers A pseudo waveguide that is coupled to the pseudo-coaxial line via the converter using a metal pattern formed on the upper and lower layers of the side walls as the left and right side walls and the upper and lower walls, and the pseudo waveguide is configured. A film resistor disposed on the same layer surface as the metal pattern is provided.

  According to the present invention, the termination resistor can be disposed in the multilayer substrate integrally with the semiconductor switch, so that the number of components can be reduced, the package can be reduced in size, and the power durability equivalent to that of the prior art can be achieved. There is an effect that can be achieved.

FIG. 1 is a plan view showing a configuration of a microwave package according to Embodiment 1 of the present invention. 2 is a cross-sectional view taken along line A-A ′ shown in FIG. 1. FIG. 3 is a plan view showing a configuration of a comparative example microwave package. FIG. 4 is a cross-sectional view taken along line A-A ′ shown in FIG. 3. FIG. 5 is a cross-sectional view showing the configuration of the microwave package according to the second embodiment of the present invention. FIG. 6 is a cross-sectional view showing the configuration of the microwave package according to the third embodiment of the present invention.

  Embodiments of a microwave package according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a plan view showing a configuration of a microwave package according to Embodiment 1 of the present invention. FIG. 2 is a cross-sectional view taken along line AA ′ shown in FIG.

  In the figure, the microwave package according to the first embodiment is composed of a multilayer substrate 6. The multilayer substrate 6 is placed on a metal plate 18 serving as a heat dissipation surface. In the multilayer substrate 6, metal patterns 17a to 17h and a cavity 8 are formed. The interlayers of the metal patterns 17a to 17h are electrically connected by interlayer vias (or through holes: hereinafter simply referred to as “vias”) 2.

  An input end 7a of a semiconductor switch (high-power microwave switch) 7 mounted in the cavity 8 is an input end of a microwave signal, and is connected to a pad 15 formed on the metal pattern 17a by a bonding wire 9a. Yes. The pad 15 is connected to the external terminal 12 through the via 2, the strip line 11 a and the via 2.

  One switching output terminal 7b of the semiconductor switch 7 is an output terminal connected to the low noise amplifier (low noise amplifier side output terminal) and is connected to the pad 14 formed on the metal pattern 17a by the bonding wire 9b. ing. The pad 14 is connected to the external terminal 13 through the via 2, the strip line 11 b and the via 2.

  The other switching output terminal 7c of the semiconductor switch 7 is a terminal output terminal, and is connected to one end of the microstrip line 3 formed in the metal pattern 17a by a bonding wire 9c. The other end of the microstrip line 3 is connected to the central conductor of the pseudo coaxial line 4. A seal ring 10, which is a metal wall, is mounted on the upper surface of the multilayer substrate 6 so as to surround them. The upper opening of the seal ring 10 is closed by a metal cover 16.

  The pseudo coaxial line 4 has a via 2a connecting the metal pattern 17a formed on the upper surface of the uppermost layer and the metal pattern 17h formed on the lower surface of the lowermost layer as a central conductor, and has two or more layers around it. Interlayer vias 2 that are connected and arranged in an annular shape are used as outer conductors. Since the interlayer vias 2 forming the outer conductor are arranged at intervals sufficiently smaller than the wavelength of the input microwave signal, they operate equivalently as coaxial lines.

  The pseudo coaxial line 4 is coupled to the pseudo waveguide 5 via a coaxial line / waveguide converter. That is, in the pseudo waveguide 5, the metal pattern 17 d is an upper metal wall, the metal pattern 17 g is a lower metal wall, and the left and right metal walls are formed by the interlayer vias 2. Since the interlayer vias 2 forming the left and right metal walls are arranged at a sufficiently small interval compared to the wavelength of the input microwave signal, they operate equivalently as a waveguide. And the film resistor 1 is arrange | positioned in the formation layer of the metal pattern 17g near the metal plate 18 which is a heat radiating surface.

  In the coaxial line / waveguide converter, the interlayer via 2a that forms the central conductor of the pseudo-coaxial line 4 is short-circuited by the metal pattern 17g that forms the bottom metal wall of the pseudo-waveguide 5 (FIG. 2 (a)). Or by disposing the short-circuited surface of the pseudo-waveguide 5 at a position which is opened in the pseudo-waveguide 5 (FIG. 2 (b)) and is about a quarter wavelength away from the short-circuited point or the open-point. It is formed.

  The operation will be described below. The semiconductor switch 7 is controlled to the termination side ON state at the timing or period when the transmission system performs the transmission operation, and is controlled to the termination side OFF state at the time of operation of the reception system. When the semiconductor switch 7 is controlled to be in the terminal-side ON state, the microwave signal input from the external terminal 12 is transmitted through the interlayer via 2, the strip line 11a, the interlayer via 2, the pad 15, and the bonding wire 9a. 7 to the input terminal 7a.

  Since the semiconductor switch 7 is in the terminal-side ON state, the microwave signal guided to the input terminal 7 a is output from the terminal-side output terminal 7 c to the microstrip line 3. The microwave signal input to the microstrip line 3 is guided to the pseudo-coaxial line 4 via the microstrip line / coaxial line converter, and is guided to the pseudo-waveguide 5 via the coaxial line / waveguide converter. It is burned.

  The microwave signal guided to the pseudo waveguide 5 is terminated by being converted into heat by the film resistor 1 arranged in the same layer as the metal pattern 17 g forming the lower metal wall of the pseudo waveguide 5. The Here, the impedance mismatch can be suppressed by setting the resistance value of the film resistor 1 to the same level as the impedance Zin of the coaxial / waveguide conversion portion expressed by the equation (1).

Zin = 600b / [a × √ {1- (fc / f) ² }] (1)
In Equation (1), a is the width of the pseudo waveguide 5, b is the height of the pseudo waveguide 5, fc is the cutoff frequency of the pseudo waveguide 5, and f is the center frequency of the microwave package. is there.

  Next, when the conductor switch 7 is in the terminal-side OFF state, the microwave signal input from the external terminal 12 passes through the inter-via 2, the strip line 11b, the interlayer via 2, the pad 15, and the bonding wire 9a. It is led to the input terminal 7 a of the semiconductor switch 7.

  Since the semiconductor switch 7 is in the termination side OFF state, the microwave signal guided to the input terminal 7a is sent from the low noise amplifier side output terminal 7b to the bonding wire 9, the pad 14, the interlayer via 2, the strip line 11b, The signal is output to the external terminal 13 through the interlayer via 2.

  Here, for ease of understanding, a comparative microwave package having a configuration in which a termination resistor is externally attached will be described with reference to FIGS. 3 and 4. FIG. 3 is a plan view showing a configuration of a comparative example microwave package. FIG. 4 is a cross-sectional view taken along line A-A ′ shown in FIG. 3.

  In the figure, in the comparative example microwave package, a multilayer substrate 19 and a dielectric substrate 23 are arranged on a metal plate 18. The multilayer substrate 19 is the same as the multilayer substrate 6 in that the metal patterns 17a to 17h and the cavity 8 are formed, but the pseudo coaxial line 4 and the pseudo waveguide 5 shown in FIGS. 1 and 2 are formed. Absent.

  The terminal-side output end 7c of the semiconductor switch 7 mounted in the cavity 8 is connected to the external terminal 20 through the bonding wire 9c, the pad 24, the interlayer via 2, the strip line 25, and the interlayer via 2.

  A microstrip line 21 made of a metal pattern and a film resistor 1 are formed on the upper surface of the dielectric substrate 23, and one end of the film resistor 1 is grounded to the metal plate 18 through the side metal pattern 22. . The microstrip line 21 is connected to the external terminal 20 via a bonding wire 26.

  The operation when the semiconductor switch 7 is in the termination side ON state will be described. The microwave signal input from the external terminal 12 is guided to the input end 7a of the semiconductor switch 7 through the interlayer via 2, the strip line 11a, the interlayer via 2, the pad 15, and the bonding wire 9a. Since the semiconductor switch 7 is in the terminal-side ON state, the microwave signal guided to the input terminal 7a is transmitted from the terminal-side output terminal 7c to the bonding wire 9c, the pad 24, the interlayer via 2, the strip line 25, and the interlayer via. 2 to the external terminal 20.

  The microwave signal guided to the external terminal 20 is guided to the microstrip line 21 on the dielectric substrate 23 via the bonding wire 26 and input to the film resistor 1 whose tip is short-circuited by the side metal pattern 22. The film resistor 1 is terminated by being converted to heat.

  The operation in the case where the semiconductor switch 7 is in the termination side OFF state is the same as that described in the example in which the switch device is configured using the high power withstand voltage termination resistor according to the first embodiment.

  As described above, according to the comparative example microwave package, as in the first embodiment, the microwave package including the switch device that can switch the terminal state and the passing state depending on the state of the semiconductor switch 7 is provided. Can be realized. However, the switch device configured as shown in FIG. 3 requires two components, that is, a microwave package storing only a semiconductor switch and a termination resistor connected to the outside of the microwave package. In addition, it is necessary to connect the microwave package storing only the switch and the terminating resistor with a bonding wire, leading to deterioration of reflection characteristics at the connection portion.

  On the other hand, in the switch device that can switch the terminal state and the passing state according to the state of the semiconductor switch 7 according to the first embodiment, the semiconductor switch 7 and the film resistor (termination resistor) 1 are connected to the microwave. Since it can be integrally formed in the package, it is possible to achieve high performance by reducing the number of components, downsizing the device, and reducing the number of connections.

  Further, the film resistor 1 that generates heat can be disposed at a position near the metal plate 18 serving as a heat radiating surface, and a thermal via serving as a heat conduction path can be disposed at a position near the film resistor 1, so It can be released efficiently. In addition, since the film resistor 1 can be formed in the same size as the lateral width of the pseudo-waveguide 5, the heat density generated in the film resistor 1 can be reduced. Power durability can be realized.

Embodiment 2. FIG.
FIG. 5 is a cross-sectional view showing the configuration of the microwave package according to the second embodiment of the present invention. In FIG. 5, the same reference numerals are given to components that are the same as or equivalent to those shown in FIG. 2 (Embodiment 1). Here, the description will be focused on the portion related to the second embodiment.

  As shown in FIG. 5, a configuration using a strip line 31 may be used instead of the microstrip line 3 used in the first embodiment. Although not shown, a coplanar line may be used instead of the microstrip line 3.

Embodiment 3 FIG.
FIG. 6 is a cross-sectional view showing the configuration of the microwave package according to the third embodiment of the present invention. In FIG. 6, the same reference numerals are given to the same or equivalent components as those shown in FIG. 2 (Embodiment 1). Here, the description will focus on the part related to the third embodiment.

  As shown in FIG. 6, not only the film resistor 1 is arranged on the metal pattern 17g constituting the lower surface of the pseudo waveguide 5, but also the film resistor 33 is arranged on the metal pattern 17d constituting the upper surface of the pseudo waveguide 5. It is good also as a structure arrange | positioned.

  As described above, the microwave package according to the present invention is useful as a microwave package that can reduce the number of parts, reduce the size of the package, and improve the performance of the termination processing of leaked transmission microwave signals. It is.

1,33 Membrane resistor (Terminal resistor)
2 Interlayer via (through hole)
2a Interlayer via constituting central conductor of pseudo coaxial line 3 Micro strip line 4 Pseudo coaxial line 5 Pseudo waveguide 6 Multilayer substrate 7 High power microwave switch (semiconductor switch)
7a Input end 7b Low noise amplifier side output end 7c Termination side output end 8 Cavity 9a, 9b, 9c Bonding wire 10 Seal ring 11, 31 Strip line 12, 13 External terminal 14, 15 Pad 16 Cover 17a-17h Metal pattern 18 Metal Board

Claims (6)

A semiconductor switch controlled to switch and output a microwave signal input to the input terminal to either the terminal output terminal or the low noise amplifier output terminal is provided on the multilayer substrate. A microwave package implemented as one,
In the multilayer substrate,
A via or through hole that connects between the metal pattern formed on the upper surface of the uppermost layer and the metal pattern formed on the lower surface of the lowermost layer is used as a central conductor, and two or more layers are connected around it and arranged in an annular shape. A pseudo-coaxial line having an interlayer via or interlayer through hole as an outer conductor,
A microstrip line that connects a terminal-side output end of the semiconductor switch and a central conductor of the pseudo-coaxial line;
Pseudo-waveguides that are connected to the pseudo-coaxial line via the conversion section using a row of interlayer vias or interlayer through-holes connecting two or more layers as side walls and metal patterns formed on the upper and lower layers of the side walls as upper and lower walls. Tube,
A microwave package comprising: the metal pattern constituting the pseudo waveguide; and a film resistor disposed on the same layer surface. The membrane resistor is
The microwave package according to claim 1, wherein the microwave package is disposed on a surface close to a heat dissipation surface of the pseudo waveguide. The lateral width of the membrane resistor is
The microwave package according to claim 1, wherein the microwave package has a width equal to a width of the pseudo waveguide. The resistance value of the membrane resistor is
When a is the width of the pseudo waveguide, b is the height of the pseudo waveguide, fc is the cutoff frequency of the pseudo waveguide, and f is the center frequency of the microwave package,
The microwave package according to claim 1, wherein the microwave package is about 600 b / [a × √ {1- (fc / f) ² }].   The microwave package according to any one of claims 1 to 4, wherein a strip line is formed instead of the micro strip line.   The microwave package according to claim 1, wherein a coplanar line is formed instead of the microstrip line.

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