JP2018050276A - Microwave semiconductor device - Google Patents

Abstract

Provided is a microwave semiconductor device capable of smoothing a voltage applied to a high-frequency semiconductor element even when a baseband frequency is increased to 100 MHz. A microwave semiconductor device includes a package, a semiconductor amplifying element, an output matching circuit, and a smoothing circuit. The package includes a metal base plate 200, a frame 16, an input feedthrough portion 20a, and an output feedthrough portion 20b. The output matching circuit includes at least the output matching capacitor 32 and the first bonding wire 14. The smoothing circuit includes smoothing capacitors 34a and 34b and second bonding wires 23a and 23b. The smoothing capacitor is connected by a second bonding wire at a position in the output matching circuit where the capacitive reactance component of the load impedance is smaller than the inductive reactance component of the load impedance viewed from the output electrode of the semiconductor amplifying element. [Selection] Figure 1

Description

  Embodiments described herein relate generally to a microwave semiconductor device.

  Some digital communication systems have a baseband frequency of 100 MHz.

  When the baseband frequency is near 100 MHz, the voltage applied to the output electrode of the high-frequency semiconductor amplifying element can be smoothed by disposing a capacitor near the output terminal of the amplifier.

  On the other hand, when the baseband frequency is as high as 100 MHz, a capacitor provided in the vicinity of the output terminal of the internal matching microwave semiconductor amplifier in which a matching circuit is provided between the high-frequency semiconductor amplifying element and the output terminal is connected to the output electrode. It becomes difficult to smooth the applied voltage.

JP 2012-235223 A

  Provided is a microwave semiconductor device capable of smoothing a voltage applied to an output electrode of a high-frequency semiconductor element even when a baseband frequency is increased to 100 MHz.

  The microwave semiconductor device according to the embodiment includes a package, a semiconductor amplifying element, an output matching circuit, and a smoothing circuit. The package includes a metal base plate, a frame joined to the surface of the metal base plate, an input feedthrough portion fitted and joined to the surface of the metal base plate, and the metal base An output feedthrough portion that is fitted and joined to the frame body at a position facing the input feedthrough portion on the surface of the plate. The semiconductor amplifying element is bonded to a region surrounded by the frame body on the surface of the metal base plate, has an output electrode, and has a rectangular planar shape. The output matching circuit is provided in a region between the semiconductor amplifying element and the output feedthrough portion in the surface of the metal base plate, and is arranged along a long side direction of the semiconductor amplifying element. A matching capacitor; and a first bonding wire connected to the output matching capacitor and the output electrode. The smoothing circuit includes a smoothing capacitor provided in a region adjacent to the short side of the semiconductor amplifying element on the surface of the metal base plate, and a second bonding wire. The smoothing capacitor is formed by the second bonding wire at a position in the output matching circuit where the capacitive reactance component of the load impedance is smaller than the inductive reactance component of the load impedance viewed from the output electrode of the semiconductor amplifying element. Connected.

FIG. 1A is a schematic plan view of the microwave semiconductor device according to the first embodiment, and FIG. 1B is a schematic cross-sectional view taken along the line A-A ′. FIG. 2A is an equivalent circuit diagram of the microwave semiconductor device according to the first embodiment, and FIG. 2B is a schematic plan view of the semiconductor amplifying element. It is a Smith figure explaining the locus of impedance conversion of the microwave semiconductor device concerning a 1st embodiment, and the connecting position of a smoothing circuit. FIG. 4A is a schematic plan view of a microwave semiconductor device according to a comparative example, and FIG. 4B is a Smith diagram illustrating the locus of impedance conversion and the connection position of the smoothing circuit. It is a schematic plan view of the microwave semiconductor device concerning 2nd Embodiment. It is an equivalent circuit diagram of the microwave semiconductor device concerning a 2nd embodiment. It is a Smith figure explaining the locus of load impedance conversion of a microwave semiconductor device concerning a 2nd embodiment, and the connecting position of a smoothing circuit. It is a schematic plan view of the microwave semiconductor device concerning the modification of 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is a schematic plan view of the microwave semiconductor device according to the first embodiment, and FIG. 1B is a schematic cross-sectional view along the line AA ′.
FIG. 1A is a schematic plan view excluding the lid 10.
2A is an equivalent circuit diagram of the microwave semiconductor device according to the first embodiment, and FIG. 2B is a schematic plan view of the semiconductor amplifying element.

  The microwave semiconductor device 1 includes a package, a semiconductor amplification element 24, an output matching circuit 82, and a smoothing circuit 90. The output matching circuit 82 includes at least the output matching capacitor 32 and the first bonding wire 14.

  The package includes a metal base plate 200, a frame body 16 made of metal or the like bonded to the surface of the metal base plate 200, an input feedthrough portion 20 a fitted in the frame body 16 and bonded to the surface of the metal base plate 200, An output feedthrough 20b that is fitted into the frame 16 and joined to the surface of the metal base plate 200 at a position facing the input feedthrough 20a. The input feedthrough portion 20a has an input lead 21a, and the output feedthrough portion 20b has an output lead 21b. The metal base plate 200 can be Cu, CuW, CuMo, or the like.

  The semiconductor amplifying element 24 is bonded to a region surrounded by the frame 16 on the surface of the metal base plate 200. The semiconductor amplifying element 24 may be a HEMT (High Electron Mobility Transistor), a MESFET (Metal Semiconductor Field Effect Transistor), or the like. The semiconductor amplifying element 24 can have an input electrode G and an output electrode D on the upper surface of the chip, as shown in FIG. In addition, a ground electrode S can be provided on the lower surface of the chip through a via hole provided in the chip. The semiconductor amplifying element 24 has a rectangular planar shape composed of a long side 24a and a short side 24b, and includes a cell region serving as a minimum unit having an amplifying function along the long side 24a.

  The output matching capacitor (C2) 32 is joined to a region between the output electrode D and the output feedthrough portion 20b on the surface of the metal base plate 200. The first bonding wire (L3) 14 connects the output electrode D and the output matching capacitor 32. The output matching capacitor 32 is arranged in parallel along the long side 24 a of the semiconductor amplifying element 24.

  In addition, the microwave semiconductor device 1 can include an input matching capacitor (C1) 30, a bonding wire (L1) 13, and a bonding wire (L2) 12.

Further, the microwave semiconductor device 1 can include an input distribution constant circuit 17 and an output distribution constant circuit 18. The input distributed constant circuit 17 is configured by providing a microstrip line or the like on a ceramic substrate 26 such as Al ₂ O ₃ . The output distribution constant circuit 18 is configured by providing a microstrip line or the like on a ceramic substrate 28 such as Al ₂ O ₃ .

  2A, an output matching circuit (impedance conversion circuit) 82 of the microwave semiconductor device 1 includes a first bonding wire 14, an output matching capacitor 32, a bonding wire (L4) 19, and an output distribution constant circuit 18. Have. The input matching circuit (impedance conversion circuit) 80 of the microwave semiconductor device 1 includes an input distributed constant circuit 17, a bonding wire 13, an input matching capacitor 30, and a bonding wire 12. The input matching capacitor 30 and the output matching capacitor 32 have a structure in which a dielectric layer having a high relative dielectric constant such as 40 to 280 is sandwiched between upper and lower electrodes, so that each matching circuit can be reduced in size. .

The smoothing circuit 90 includes a smoothing capacitor 34 and a second bonding wire (L _B ) 23. The smoothing capacitor 34 (34a, 34b) is joined to the surface of the metal base plate 200 so as to be adjacent to the short side 24b of the semiconductor amplifying element 24. The second bonding wires 23 (23a, 23b) connect the smoothing circuit 90 and a predetermined position of the output matching circuit 82.

  The smoothing capacitor 34 may have a structure in which a dielectric layer having a high relative dielectric constant is sandwiched between upper and lower electrodes. As shown in FIG. 1A, the smoothing capacitor 34 can be provided in a region adjacent to the semiconductor amplifying element 24.

  When the microwave semiconductor device 1 is desired to have a high output, the semiconductor amplifying element 24 may have a multi-cell configuration in which cell regions are arranged in parallel.

In FIG. 2A, the smoothing circuit 90 is connected to the output matching capacitor 32 at the connection position N1. The capacitance of the smoothing capacitor 34 is C _BR , the current amplitude value is I _PK , the allowable ripple voltage value is ΔV, and the baseband frequency value is Δf. If C _BR ≧ I _PK × (1 / 2πΔf) / ΔV, the applied voltage at the output electrode of the semiconductor amplifying element 24 caused by the baseband frequency component can be smoothed.

  At the operating frequency, the wires are such that the inductance component of the second bonding wire 23 (23a, 23b) constituting the smoothing circuit 90 is sufficiently higher than the load impedance of the matching circuit at the connection position of the smoothing circuit 90. By setting the length, the operating frequency component leaking to the smoothing capacitor 34 is reduced. That is, the smoothing circuit 90 is provided so as not to affect the operating frequency signal.

  On the other hand, if the second bonding wire 23 (23a, 23b) is too long as the impedance increases even at the baseband frequency, the effect of the smoothing capacitor 34 is weakened, and the applied voltage at the output electrode of the semiconductor amplifying element 24 cannot be smoothed. .

FIG. 3 is a Smith diagram illustrating load impedance conversion of the microwave semiconductor device according to the first embodiment.
This figure represents the normalized impedance when the characteristic impedance (Z _C ) is 50Ω. The resistance component of the semiconductor amplifying element 24 is, for example, in the vicinity of 2.5Ω, and has an output capacitance in parallel therewith. It becomes.

  The magnitude of the operating frequency component leaking to the smoothing capacitor 34 is determined by the impedance ratio at the operating frequency of the smoothing circuit 90 and the load impedance of the matching circuit at the connection position of the smoothing circuit 90. The load impedance Z2 viewed from the second reference plane Q2 before applying inductive reactance by the first bonding wire 14 is capacitive.

  The capacitive reactance component of the load impedance Z2 is smaller than the inductive reactance component of the load impedance Z1. For this reason, since the load impedance Z2 of the output matching circuit 82 at the connection position N1 of the output matching circuit 82 is smaller than the load impedance Z1 at the output electrode D of the semiconductor amplifier 24, the second bonding wire 23a of the smoothing circuit 90, Even if 23b is shortened, the impedance ratio at the operating frequency of the smoothing circuit 90 with respect to the load impedance at the operating frequency of the output matching circuit at the connection position of the smoothing circuit 90 can be kept large. As a result, it is possible to reduce the impedance at the baseband frequency of the second bonding wires 23a and 23b of the smoothing circuit 90 while sufficiently reducing the operating frequency component leaking to the smoothing capacitor 34. The effect of the smoothing capacitor 34 is increased.

FIG. 4A is a schematic plan view of a microwave semiconductor device according to a comparative example, and FIG. 4B is a Smith diagram for explaining the load impedance conversion.
This figure, the characteristic impedance Z _C represents the normalized impedance when the 50 [Omega. In the comparative example, the bonding wire 23 a of the smoothing circuit 190 is connected to the output electrode (not shown) of the semiconductor amplifying element 24. That is, the inductive reactance of the load impedance Z1 viewed from the connection position N2 is larger than the capacitive reactance of the load impedance Z2 viewed from the second reference plane Q2 by the amount that the inductive reactance by the first bonding wire 14 is added.

  Since the load impedance Z1 at the operating frequency of the connection position N2 is higher than the load impedance Z2, the second bonding wire 23a of the smoothing circuit 190 is lengthened to increase the impedance of the smoothing circuit 190 at the operating frequency, and the smoothing capacitor It is necessary to reduce the operating frequency component leaking to 134a and 134b. As a result of lengthening the second bonding wire 23a, the impedance of the smoothing circuit 190 at the baseband frequency of the second bonding wire 23a increases, and the effect of the smoothing capacitor 134 at the baseband frequency decreases.

FIG. 5 is a schematic plan view of the microwave semiconductor device according to the second embodiment.
FIG. 6 is an equivalent circuit diagram of the microwave semiconductor device according to the second embodiment.
FIG. 7 is a Smith diagram illustrating the load impedance of the microwave semiconductor device according to the second embodiment.

  The lowest impedance point in the impedance conversion circuit is when a part of the inductance of the first bonding wire 14 of the matching circuit cancels out the output capacitance component of the semiconductor amplifying element 24, and is a point on the real axis in the Smith diagram. When the connection position N3 between the smoothing circuit 90 and the output matching circuit 82 is set to the lowest impedance point in the impedance conversion circuit, the second bonding wires 23 (23a, 23b) of the smoothing circuit 90 can be made the shortest, and the smoothing capacitor 34 ( The effect of 34a, 34b) can be maximized. In FIG. 5, a relay substrate 94 having bonding electrodes (not shown) is further provided between the semiconductor amplifying element 24 and the output matching capacitor 32. The relay substrate 94 is disposed along the long side 24 a of the semiconductor amplifying element 24. The first bonding wire 14 can be divided into two by the relay substrate 94 to create the connection position N3.

  The output electrode D of the semiconductor amplifying element 24 and the bonding electrode of the relay substrate 94 are connected by the first portion 14 a of the first bonding wire 14. Further, the bonding electrode of the relay substrate 94 and the output matching capacitor 32 are connected by the second portion 14 b of the first bonding wire 14. The first portion 14a of the first bonding wire 14 and the second portion 14b of the first bonding wire 14 may be continuous. For example, when an automatic wire bonder is used, it is easy to make the first portion 14a and the second portion 14b continuous. The second bonding wires 23 (23a, 23b) are connected to the bonding electrodes of the relay substrate 94.

  In this case, in FIG. 7, the connection position N3 is in the vicinity of Z2 @ Q2, which is the point where the load impedance of the impedance conversion circuit intersects the real axis of the Smith diagram (pure resistance not including the reactance component but including only the resistance component). To be determined. That is, the first portion 14a of the first bonding wire 14 and the second portion 14b of the first bonding wire 14 have an inductance component that resonates at the operating frequency with the output capacitance component of the semiconductor amplifying element 24. Is provided. In this way, the connection position N3 between the smoothing circuit 90 and the output matching circuit 82 can be the lowest impedance point in the impedance conversion circuit, and the effect of the smoothing capacitor 34 (34a, 34b) can be maximized. Since the relay substrate 94 does not need to form a capacitor, the relay substrate should have a lower relative dielectric constant.

FIG. 8 is a schematic plan view of a microwave semiconductor device according to a modification of the second embodiment.
In the present modification, an auxiliary substrate 95 having a bonding electrode (acting as an auxiliary smoothing capacitor) is further provided between the semiconductor amplifying element 24 and the output matching capacitor 32. Further, a third bonding wire 15 that connects the output matching capacitor 32 and the bonding electrode of the auxiliary smoothing capacitor 95 is further provided. By connecting a smoothing circuit via the auxiliary smoothing capacitor 95, the effect of the smoothing capacitor can be evenly distributed to a plurality of cells connected in parallel. By setting the connection position of the third bonding wire 15 to the connection position N1 in which the load impedance at the operating frequency is smaller than the connection position N2, the bonding wire 23a of the smoothing circuit is shortened and the second bonding wire 23a of the smoothing circuit is shortened. Since the impedance at the baseband frequency can be reduced, the effect of the smoothing capacitor 34a at the baseband frequency is enhanced. Further, since the smoothing circuit is evenly connected to the plurality of cells connected in parallel, the influence on the operating frequency is reduced.

  According to the first and second embodiments and the modifications associated therewith, there is provided a microwave semiconductor device capable of smoothing the voltage applied to the high-frequency semiconductor amplifying element even when the differential frequency is as high as several hundred MHz. Is done. This microwave semiconductor device can be used in communication systems such as SNG (Satellite News Gathering) and MIMO (Multiple Input Multiple Output) that use two or more microwave signals having close frequencies.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 Microwave semiconductor device, 14, 14a, 14b 1st bonding wire, 15 3rd bonding wire, 16 Frame, 18 Output distribution constant circuit, 20a Input feedthrough part, 20b Output feedthrough part, 23, 23a, 23b First 2 bonding wires, 24 semiconductor amplification elements, 24a long side, 24b short side, 32 output matching capacitor, 34 smoothing capacitor, 82 output matching circuit, 90 smoothing circuit, 94 relay board, 95 auxiliary board (auxiliary smoothing capacitor) ), 200 Metal base plate, Z1-Z5 load impedance, N1-N3 (smoothing circuit) connection position, G (semiconductor amplifier element) input electrode, D (semiconductor amplifier element) output electrode

Claims (7)

A metal base plate, a frame joined to the surface of the metal base plate, an input feedthrough part fitted and joined to the surface of the metal base plate, and the surface of the metal base plate An output feedthrough part fitted and joined to the frame body at a position facing the input feedthrough part,
A semiconductor amplifying element that is bonded to a region surrounded by the frame body of the surface of the metal base plate, has an output electrode, and has a rectangular planar shape;
Of the surface of the metal base plate, provided in a region between the semiconductor amplifying element and the output feedthrough portion, the output matching capacitor disposed along the long side direction of the semiconductor amplifying element, An output matching circuit having an output matching capacitor and a first bonding wire connected to the output electrode;
A smoothing circuit having a smoothing capacitor provided in a region adjacent to the short side of the semiconductor amplifying element of the surface of the metal base plate; and a second bonding wire;
With
The smoothing capacitor is formed by the second bonding wire at a position in the output matching circuit where the capacitive reactance component of the load impedance is smaller than the inductive reactance component of the load impedance viewed from the output electrode of the semiconductor amplifying element. A connected microwave semiconductor device.   The microwave semiconductor device according to claim 1, wherein the smoothing capacitor is connected to the output matching capacitor by the second bonding wire. The output matching circuit is provided in the region between the semiconductor amplifying element and the output matching capacitor in the surface of the metal base plate along the long side direction of the semiconductor amplifying element, and bonded to the surface. Further having a relay substrate having a working electrode,
The first bonding wire has a first portion that connects the output electrode and the bonding electrode, and a second portion that connects the bonding electrode and the output matching capacitor,
The microwave semiconductor device according to claim 1, wherein the smoothing capacitor is connected to the bonding electrode by the second bonding wire.   The microwave semiconductor device according to claim 3, wherein the first portion of the first bonding wire has an inductance component that resonates with an output capacitance component of the semiconductor amplifying element at an operating frequency.   The microwave semiconductor device according to claim 3 or 4, wherein a load impedance viewed from the bonding electrode is a pure resistance. The smoothing circuit is provided along the long side of the semiconductor amplifying element in a region between the output electrode and the output matching capacitor in the surface of the metal base plate. An auxiliary substrate, a third bonding wire connecting the output matching capacitor and the bonding electrode of the auxiliary substrate,
Further comprising
The microwave semiconductor device according to claim 1, wherein the smoothing capacitor is connected to the bonding electrode of the auxiliary substrate by the second bonding wire.   The microwave semiconductor device according to claim 1, wherein the output matching circuit further includes an output distributed constant circuit provided between the output matching capacitor and the output feedthrough unit.

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