JP2016111100A - Power amplifier circuit and communication device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power amplifier circuit that suppresses parasitic capacitance between an emitter and a collector, and suppresses heat increase even when outputting high power with a high frequency.SOLUTION: The power amplifier circuit includes: a lower layer metal 11 on which an emitter or a collector is wired; and an upper layer metal 12 on which a collector or an emitter is wired. The upper layer metal 12 is thinned out in terms of area, and, in the area where the upper layer metal 12 is thinned out, the wiring of the lower layer metal 11 is extracted to a height of the upper layer metal 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a power amplifier circuit and a communication device.

  Semiconductor devices such as diodes, transistors, MOS-FETs (metal-oxide-field-effect transistors), and semiconductor integrated circuits in which drive control circuits for these semiconductor devices are integrated on a single silicon substrate ((Integrated Circuit; IC) has been developed.

  A transistor of a power amplifier connected to an antenna that performs wireless communication in a cellular phone or the like is required to have a high frequency and high power output. In a semiconductor IC for realizing a high power output at a high frequency, a high power output is often obtained by arranging a plurality of bipolar transistors (bipolar transistors) having the same layout pattern with a small size. When the bipolar transistor outputs high power, large heat is generated. It has been known that the heat becomes non-uniform among a plurality of arranged bipolar transistors, and only some of the transistors thermally oscillate, resulting in unstable operation.

  Therefore, a technique for making the heat generated in the bipolar transistor uniform between the bipolar transistors has been proposed. For example, in Non-Patent Document 1, a bipolar transistor group in which bipolar transistor emitter wiring is formed by forming a thick metal layer on the uppermost layer immediately above the pattern region of the bipolar transistor. A technique for making the heat uniform and suppressing heat is disclosed.

Microwave Symposium Digest, 1997., IEEE MTT-S International, pp949-952 vol.2, Power performance of thermally-shunted heterojunction bipolartransistors, Jenkins, T. et.al.,

  However, even if the conventional technique disclosed in Non-Patent Document 1 is used, the transistor density must be increased in order to reduce the size of the semiconductor IC due to cost and mounting requirements. Along with the rise, there is a problem that it is difficult to suppress the rise in heat. Further, in a power amplifier realized using an integrated circuit of bipolar transistors, when a high power is output, a large current flows through the emitter and the collector. Therefore, the emitter and the collector need to be relatively thick. However, when the emitter and collector are made thick, there is a problem that a large parasitic capacitance is added between the emitter and the collector.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to suppress the parasitic capacitance between the emitter and the collector and to perform heat output even when high power is output at a high frequency. It is an object of the present invention to provide a new and improved power amplification circuit and communication device capable of suppressing the increase.

  In order to solve the above-described problems, according to one aspect of the present invention, a lower layer metal to which an emitter or a collector is wired and an upper layer metal to which a collector or an emitter is wired are provided, and the upper layer metal is thinned out in area. A high-frequency amplifier circuit is provided, wherein the lower metal layer wiring is drawn out in a region where the upper metal layer is thinned out.

  The wiring drawn from the lower layer metal may be located on the ground back via.

  The wiring drawn from the lower layer metal may be arranged in a region surrounded by at least three sides of the thinned upper layer metal.

  The wiring drawn from the lower metal layer may be drawn to the height of the upper metal layer.

  Pads may be formed on the wiring drawn from the lower layer metal, and the pads may be connected by wire bonding.

  Pads may be formed on the wiring drawn from the lower layer metal, and the pads may be connected by metal wiring.

  In order to solve the above problems, according to another aspect of the present invention, there is provided a communication apparatus including the high-frequency amplifier circuit.

  As described above, according to the present invention, a new and improved power amplification capable of suppressing the parasitic capacitance between the emitter and the collector and suppressing the increase in heat even when high power is output at a high frequency. Circuits and communication devices can be provided.

It is explanatory drawing which shows the high frequency power amplifier 10 which concerns on one Embodiment of this invention with a top view. It is explanatory drawing which shows the high frequency power amplifier 100 which concerns on one Embodiment of this invention with a top view. FIG. 3 is an explanatory diagram schematically showing a cross section of the high-frequency power amplifier 100 shown in FIG. 2. 3 is an explanatory diagram schematically showing a cross section of a high-frequency power amplifier 100. FIG. 3 is an explanatory diagram schematically showing a cross section of a high-frequency power amplifier 100. FIG. It is explanatory drawing which shows the structural example of the radio | wireless communication apparatus 1000 provided with the high frequency power amplifier 100 which concerns on one Embodiment of this invention.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<1. Background>
First, before describing the embodiment of the present invention in detail, the background of the embodiment of the present invention will be described.

  As described above, a transistor of a power amplifier connected to an antenna that performs wireless communication in a mobile phone or the like is required to have a high frequency and high power output. In a semiconductor IC for realizing a high power output at a high frequency, a high power output is obtained by arranging a plurality of bipolar transistors of the same layout pattern with small dimensions.

  In a power amplifier realized using an integrated circuit of bipolar transistors, a large number of bipolar transistors that output high power at a high frequency are arranged in the same layout pattern. Current flows. In order to allow a large current to flow through the emitter and collector, the emitter and collector need to be relatively thick.

  However, when the emitter and collector wires are thickened, a large parasitic capacitance is added between the emitter and the collector. When the power characteristic is derived by optimizing the impedance of the output matching circuit, the power characteristic may be limited due to the parasitic capacitance between the emitter and the collector.

  In addition, in a semiconductor IC for realizing a high power output at a high frequency, a high power output is often obtained by arranging a plurality of bipolar transistors having the same layout pattern with small dimensions. When the bipolar transistor outputs high power, large heat is generated. It is known that the heat becomes non-uniform between a plurality of arranged bipolar transistors, and only some of the transistors thermally oscillate, resulting in unstable operation.

  Even if the conventional technique disclosed in Non-Patent Document 1 is used as a technique for making the heat generated in the bipolar transistor uniform between the bipolar transistors, the size of the semiconductor IC can be reduced due to cost and mounting requirements. In order to reduce the size, it is necessary to increase the density of the transistors, and there is a problem that it is difficult to suppress the heat rise.

  Therefore, in order to realize a high-power and high-power output, the present inventor has developed a specific bipolar transistor by making heat uniform between the bipolar transistors when a plurality of bipolar transistors having the same layout pattern with small dimensions are arranged. In addition, we have intensively studied the technology of a high-frequency amplifier circuit that can improve the power characteristics such as maximum output power and power efficiency by suppressing the rise in heat and the parasitic capacitance between the emitter and collector.

  As a result, the present inventor, as will be described below, thins out the upper metal layer of the collector within a predetermined range, thereby realizing bipolar transistors having the same layout pattern with small dimensions in order to achieve high power and high power output. When a plurality of transistors are arranged, the heat is uniform between the bipolar transistors to suppress the heat rise of a specific bipolar transistor, and the parasitic capacitance between the emitter and the collector is also suppressed, so that the maximum output power, power efficiency, etc. It came to devise the high frequency amplifier circuit which can improve an electric power characteristic.

  The background of the embodiment of the present invention has been described above. Next, embodiments of the present invention will be described in detail.

<2. One Embodiment of the Present Invention>
Hereinafter, an example of the high frequency amplifier circuit according to the embodiment of the present invention will be described. First, when a plurality of bipolar transistors having the same layout pattern are arranged, the upper layer metal of the collector is simply thinned out into a rectangle, thereby suppressing the parasitic capacitance between the emitter and the collector and making the heat uniform between the bipolar transistors. An example of a high-frequency amplifier circuit that makes this possible will be described.

  FIG. 1 is an explanatory diagram showing a high-frequency power amplifier 10 according to an embodiment of the present invention in a plan view. FIG. 1 shows a high frequency power amplifier 10 in which a lower layer metal 11 is formed on a semiconductor substrate such as silicon, and an upper layer metal 12 is formed on the lower layer metal 11. In the high-frequency power amplifier 10 shown in FIG. 1, the lower layer metal 11 is an emitter wiring of a bipolar transistor, and the upper layer metal 12 is a collector wiring.

  FIG. 1 shows a bipolar transistor pattern region 13 composed of an emitter and base 14 made of a lower layer metal 11 and a collector made of an upper layer metal 12.

  In the high-frequency power amplifier 10 shown in FIG. 1, the upper metal 12 is not entirely covered on the lower metal 11, but the upper metal 12 is thinned out within a predetermined range. In the example shown in FIG. 1, the upper metal 12 is thinned out so that the shape is rectangular. Of course, the size of each metal shown in the drawing and the shape and area when thinning the upper metal 12 are not limited to the example shown in FIG.

  In the plurality of bipolar transistors formed in the bipolar transistor pattern region 13, a large amount of heat is generated when high power is output. This heat does not generate much at both ends (upper and lower ends of the drawing) of the high-frequency power amplifier 10, and more heat is generated toward the central portion.

  When thinning out the upper metal 12, it is desirable to thin out the thinned area and the non-thinned area alternately in the vertical direction of the drawing as shown in FIG. By thinning the upper metal 12 in this way, it becomes possible to make the heat uniform between the bipolar transistors formed in the bipolar transistor pattern region 13. Further, as shown in FIG. 1, the upper layer metal 12 is thinned, so that the parasitic capacitance between the emitter and the collector can be suppressed.

  In FIG. 1, the high-frequency power amplifier 10 having the bipolar transistor pattern region 13 provided on the right side of the figure is shown. However, the emitter and base 14 formed of the lower metal 11 are similarly shown on the left side of the figure not shown. A bipolar transistor pattern region composed of a collector made of the upper metal 12 may be provided.

  As shown in FIG. 1, the high-frequency power amplifier 10 shown in FIG. 1 can suppress the parasitic capacitance between the emitter and the collector by thinning out the upper layer metal 12 within a predetermined range. Even in the high frequency power amplifier 10 in which the upper metal 12 is thinned out in a predetermined range as shown in FIG. 1, the heat between the bipolar transistors is made uniform and the parasitic capacitance between the emitter and the collector is suppressed. Is possible.

  An example of another high-frequency amplifier circuit is shown. FIG. 2 is an explanatory view showing the high-frequency power amplifier 100 according to one embodiment of the present invention in a plan view. FIG. 2 shows a high frequency power amplifier 100 in which a lower layer metal 101 is formed on a semiconductor substrate such as silicon and an upper layer metal 102 is formed on the lower layer metal 101. In the high frequency power amplifier 100 shown in FIG. 2, the lower layer metal 101 is an emitter wiring of a bipolar transistor, and the upper layer metal 102 is a collector wiring.

  FIG. 2 shows a bipolar transistor pattern region 103 composed of an emitter and base 104 formed of a lower layer metal 101 and a collector formed of an upper layer metal 102.

  In the high frequency power amplifier 100 shown in FIG. 2, the upper metal 102 is not entirely covered on the lower metal 101, but the upper metal 102 is thinned out within a predetermined range. In the example shown in FIG. 2, the upper metal layer 102 is thinned out so that the shape is rectangular. Of course, the size of each metal shown in the drawing and the shape and area when thinning out the upper layer metal 102 are not limited to the example shown in FIG.

  Further, the high-frequency power amplifier 100 shown in FIG. 2 leads the emitter wiring from the lower layer metal 101 to the height of the upper layer metal 102 in the region where the upper layer metal 102 is thinned out. Thus, by extracting the emitter wiring from the lower layer metal 101 to the height of the upper layer metal 102, the heat generated in the bipolar transistor formed in the bipolar transistor pattern region 103 is compared with the high frequency power amplifier 10 shown in FIG. Thus, it becomes possible to release the outside more efficiently.

  In the example shown in FIG. 2, the emitter wiring drawn to the height of the upper metal layer 102 is surrounded on all sides by the collector wiring of the upper metal layer 102, but at least three sides of the emitter wiring are surrounded by the collector wiring. It may be in the form.

  In the high-frequency power amplifier 100 shown in FIG. 2, the emitter wiring is drawn from the lower layer metal 101 to the height of the upper layer metal 102 in the region where the upper layer metal 102 is thinned out. The emitter wiring is drawn out so as to be directly above the back via 105.

  FIG. 3 is an explanatory diagram schematically showing a cross section of the high-frequency power amplifier 100 shown in FIG. As shown in FIG. 3, the high-frequency power amplifier 100 has the upper layer metal 102 thinned out in a predetermined range, and emitter wiring is connected from the lower layer metal 101 to the upper layer metal 102 in the region where the upper layer metal 102 is thinned out. Pull out to the height of. Of course, the size and width of each metal shown in the figure are not limited to those shown in the figure.

  Further, as shown in FIG. 3, in the high-frequency power amplifier 100, the emitter wiring drawn out to the height of the upper metal 102 is drawn out so as to be directly above the back via 105 formed in the semiconductor substrate 110.

  As shown in FIGS. 2 and 3, the upper layer metal 102 is thinned out within a predetermined range, and the emitter wiring is drawn from the lower layer metal 101 to the height of the upper layer metal 102 in the region where the upper layer metal 102 is thinned out. Thus, the high-frequency power amplifier 100 shown in FIGS. 2 and 3 can suppress the parasitic capacitance between the emitter and the collector.

  The high frequency power amplifier 100 shown in FIG. 2 and FIG. 3 thins the upper layer metal 102 within a predetermined range, and connects the emitter wiring from the lower layer metal 101 to the region where the upper layer metal 102 is thinned. By drawing out to the height, heat generated in the bipolar transistor formed in the bipolar transistor pattern region 103 can be released to the outside more efficiently than the high frequency power amplifier 10 shown in FIG. Become.

  Further, the high-frequency power amplifier 100 shown in FIGS. 2 and 3 is formed with an emitter wiring extending to the height of the upper metal layer 102 so as to be located immediately above the back via 105 formed in the semiconductor substrate 110. By forming the emitter wiring in this manner, the high frequency power amplifier 100 shown in FIGS. 2 and 3 can release the heat generated in the bipolar transistor formed in the bipolar transistor pattern region 103 to the back via 105. Become.

  Therefore, the high frequency power amplifier 100 shown in FIG. 2 and FIG. 3 is more efficient for the heat generated in the bipolar transistor formed in the bipolar transistor pattern region 103 than the high frequency power amplifier 10 shown in FIG. Can be released into

  Another example of a high-frequency power amplifier is shown. FIG. 4 is an explanatory diagram schematically showing a cross section of the high-frequency power amplifier 100. FIG. 4 shows that the pad 111 is arranged on the emitter wiring drawn out to the height of the upper layer metal 102 of the high frequency power amplifier 100 shown in FIG. Of course, the size and width of each metal shown in the figure are not limited to those shown in the figure.

  The high-frequency power amplifier 100 shown in FIG. 4 is shown in FIG. 3 by connecting a plurality of pads 111 formed on the emitter wiring drawn up to the height of the upper metal layer 102 with, for example, wire bonds 112. Compared with the high-frequency power amplifier 100, it can operate more thermally and stably.

  Another example of a high-frequency power amplifier is shown. FIG. 5 is an explanatory diagram schematically showing a cross section of the high-frequency power amplifier 100. FIG. 5 shows that the metal wiring 121 is arranged in the upper layer of the emitter wiring drawn out to the height of the upper metal 102 of the high-frequency power amplifier 100 shown in FIG. Of course, the size and width of each metal shown in the figure are not limited to those shown in the figure.

  The high-frequency power amplifier 100 shown in FIG. 5 is more thermally compared with the high-frequency power amplifier 100 shown in FIG. 3 by connecting the emitter wiring drawn to the height of the upper metal layer 102 by the metal wiring 121. Can operate stably.

  Subsequently, a configuration example of a wireless communication apparatus including the high-frequency power amplifier 100 according to an embodiment of the present invention will be described. FIG. 6 is an explanatory diagram illustrating a configuration example of a wireless communication apparatus 1000 including the high-frequency power amplifier 100 according to an embodiment of the present invention.

  6 includes a synthesizer 1010, a modulation circuit 1020, high frequency amplifiers 1030 and 1070, filters 1040 and 1080, an isolator 1050, a duplexer 1060, a demodulation circuit 1090, an antenna 1100, It is comprised including. As the high frequency amplifiers 1030 and 1070, the high frequency power amplifier 100 according to an embodiment of the present invention is provided.

  The synthesizer 1010 outputs a signal used for modulation of the transmission signal in the modulation circuit 1020 and demodulation of the reception signal in the demodulation circuit 1090. The modulation circuit converts the supplied transmission signal into a transmission signal having a predetermined transmission frequency. High frequency amplifier 1030 amplifies the output signal of modulation circuit 1020. The filter 1040 is composed of, for example, a band pass filter, and extracts a signal in the transmission wave band from the high frequency signal amplified by the high frequency amplifier 1030. The isolator 1050 supplies the output signal of the filter 1040 to the duplexer 1060 in one direction.

  The duplexer 1060 has three terminals: a terminal connected to the output terminal of the isolator 1050, a terminal connected to the input terminal of the high-frequency amplifier 1070, and a terminal connected to the antenna 1100.

  High frequency amplifier 1070 amplifies a signal received by antenna 1100 and output from duplexer 1060. The filter 1080 is composed of, for example, a band pass filter, and extracts a signal in the transmission wave band from the output signal of the high frequency amplifier 1070. The demodulation circuit 1090 demodulates the signal by mixing the signal extracted by the filter 1080 and the local oscillation signal supplied from the synthesizer 1010.

  The wireless communication apparatus including the high-frequency power amplifier 100 according to the embodiment of the present invention is not limited to such an example. As long as a high-frequency power amplifier that amplifies a signal in the microwave band is used, the present invention can be applied other than that shown in FIG. A wireless communication apparatus including the high-frequency power amplifier 100 according to an embodiment of the present invention can achieve low voltage operation, high efficiency, small size, and light weight.

<3. Summary>
As described above, according to one embodiment of the present invention, the upper metal layer 102 is thinned out in a predetermined range, and the emitter wiring is formed from the lower metal layer 101 to the region where the upper metal layer 102 is thinned out. A high frequency power amplifier 100 is provided.

  The high-frequency power amplifier 100 according to an embodiment of the present invention thins the upper layer metal 102 in a predetermined range as described above, and also connects the emitter wiring from the lower layer metal 101 to the upper layer metal 102 in the region where the upper layer metal 102 is thinned. It is possible to efficiently release the heat generated in the bipolar transistor formed in the bipolar transistor pattern region 103 to the outside.

  In the above embodiment, the emitter wiring is the lower metal and the collector wiring is the upper metal, but the present invention is limited to such an example. The collector wiring may be a lower metal, and the emitter wiring may be an upper metal.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

10: high frequency power amplifier 11: lower layer metal 12: upper layer metal 13: bipolar transistor pattern region 14: base 100: high frequency power amplifier 101: lower layer metal 102: upper layer metal 103: bipolar transistor pattern region 104: base 105: back via 110: semiconductor Substrate 111: Pad 112: Wire bond 121: Metal wiring 1000: Radio communication device 1010: Synthesizer 1020: Modulator circuit 1030: High frequency amplifier 1040: Filter 1050: Isolator 1060: Duplexer 1070: High frequency amplifier 1080: Filter 1090: Demodulator circuit 1100: antenna

Claims (7)

The lower metal to which the emitter or collector is wired, and
An upper metal formed on the lower metal, to which a collector or emitter is wired;
With
A high-frequency amplifier circuit characterized in that the upper metal layer is thinned in terms of area, and the wiring of the lower metal layer is drawn out in a region where the upper metal layer is thinned.   The high frequency amplifier circuit according to claim 1, wherein the wiring drawn from the lower layer metal is positioned on a ground back via.   The high frequency amplifier circuit according to claim 1, wherein the wiring drawn from the lower layer metal is disposed in a region surrounded by at least three sides of the thinned upper layer metal.   The high frequency amplifier circuit according to claim 1, wherein the wiring drawn from the lower metal is drawn to a height of the upper metal.   The high-frequency amplifier circuit according to claim 1, wherein pads are formed on the wiring drawn from the lower layer metal, and the pads are connected by wire bonds.   The high-frequency amplifier circuit according to claim 1, wherein pads are formed on wiring drawn from the lower layer metal, and the pads are connected by metal wiring. A communication apparatus comprising the high-frequency amplifier circuit according to claim 1.

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