JP5098769B2 - Switching device, switching element, and communication device - Google Patents

Description

  The present invention relates to a switching device including a minute switching element manufactured using MEMS technology, a switching element for configuring the switching device, and a communication device including the switching device.

  In the technical field of wireless communication devices such as mobile phones, there is an increasing demand for downsizing of RF circuits as the number of components mounted to realize high functions increases. In order to meet such demands, various parts constituting a circuit are being miniaturized by utilizing MEMS (micro-electromechanical systems) technology.

  A MEMS switch is known as one of such components. The MEMS switch is a switching element in which each part is minutely formed by the MEMS technology, and at least a pair of contacts for performing switching by mechanically opening and closing and a mechanical opening and closing operation of the contact pair are achieved. Drive mechanism. MEMS switches tend to exhibit higher isolation in the open state and lower insertion loss in the closed state than switching elements such as PIN diodes and MESFETs, particularly in switching high-frequency signals on the order of GHz. This is due to the fact that the open state is achieved by mechanical separation between the contact pairs and that the parasitic capacitance is low because of the mechanical switch. The MEMS switch is described in, for example, Patent Documents 1 to 5 below.

Japanese Patent Laid-Open No. 2004-1186 JP 2004-311394 A JP 2005-293918 A JP 2005-526433 A JP 2005-528751 gazette

  On the other hand, an mPnT (m-Pole n-through) type switching device having a plurality of input terminals and a plurality of output terminals is known. For example, in the technical field of communication devices such as mobile phones, there is a demand for practical use of an mPnT type switching device in order to cope with the increase in multiband communication frequency. In multiband-compatible communication devices, the connection relationship between the plurality of antennas and the plurality of RF modules is switched according to the communication frequency by the mPnT type switching device.

  It is conceivable to configure such an mPnT type switching device using a plurality of the above-described MEMS switches. When configuring an mPnT type switching device using a plurality of MEMS switches, it is necessary to connect the MEMS switches (switching elements) with a wiring pattern. As the number of switching elements constituting the device increases, the entire device increases. There is a tendency that it is difficult to set a wiring length between elements or a conductive path short while reducing the size. The longer the conductive path between elements, the greater the loss of signal passing through the switching device.

  The present invention has been conceived under the circumstances as described above, and has a plurality of input terminals and a plurality of output terminals and is suitable for miniaturization and low loss. It is an object of the present invention to provide a switching element suitable for constituting a simple switching device and a communication device including such a switching device.

  According to a first aspect of the present invention, there is provided a switching device in which a plurality of first switching elements and a plurality of second switching elements are provided on a base substrate. Each switching element in the switching device is provided on a side opposite to the base substrate in the movable portion, a fixed portion joined to the base substrate, a movable portion extending from the fixed portion and extending along the base substrate, and A movable signal electrode, a first fixed signal electrode and a second fixed signal electrode each having a portion facing the movable signal electrode, and each of which is joined to the fixed portion, and the side of the movable portion opposite to the base substrate And a fixed drive electrode having a portion facing the movable drive electrode and joined to the fixed portion. The plurality of first switching elements form a first column, and the first fixed signal electrode of each first switching element forms an input terminal. The plurality of second switching elements form a second column extending along the first column, and the first fixed signal electrode of each second switching element forms an output terminal. The second fixed signal electrodes of the plurality of switching elements are electrically connected by a common wiring pattern arranged between the first and second columns.

  In this switching device, the plurality of first fixed signal electrodes in the plurality of first switching elements are the plurality of input terminals of the device, and the plurality of first fixed signal electrodes in the plurality of second switching elements are the devices of the device. A plurality of output terminals, for example, a multi-channel capable of selecting one channel is configured between the plurality of input terminals and the plurality of output terminals. A predetermined driving voltage is applied between the fixed driving electrode and the movable driving electrode of the selected first switching element, and the fixed driving electrode and the movable driving of the selected second switching element are applied. By applying a predetermined drive voltage between the electrodes, an input terminal formed by the first fixed signal electrode of the first switching element and an output terminal formed by the first fixed signal electrode of the second switching element When electrically connected (the second fixed signal electrodes of both selected switching elements are electrically connected by the common wiring pattern), the first and second switching elements are turned on, and the first Other combinations of the first and second switching elements are turned off.

  In the present switching device, the common wiring pattern for connecting the second fixed signal electrodes of the plurality (m) of first switching elements and the second fixed signal electrodes of the plurality (n) of second switching elements. , There are m × n conductive paths, a first switching element group having a first fixed signal electrode as an input terminal of the device, and a second having a first fixed signal electrode as an output terminal of the device. The configuration in which the switching element groups are arranged in a row and are opposed to each other via the common wiring pattern reduces the size of the device and shortens the length of the mxn conductive paths and makes them uniform. It is suitable for planning. And the shorter the conductive path between the switching elements, the lower the loss of the signal passing through the device. Therefore, this switching device is suitable for downsizing and low loss.

  In the first aspect of the present invention, preferably, the common wiring pattern extends along the column between the first column formed by the first switching element group and the second column formed by the second switching element group. And a second pattern that communicates the first pattern with the second fixed signal electrode of each switching element. Such a configuration is suitable for shortening and equalizing the length of the plurality of conductive paths between the plurality of first switching elements and the plurality of second switching elements.

  Preferably, the fixed drive electrodes of the plurality of first switching elements are shared. Preferably, the fixed drive electrodes of the plurality of second switching elements are shared. These configurations are suitable for reducing the size of the apparatus.

  According to a second aspect of the present invention, there is provided another switching device in which a plurality of first switching elements and a plurality of second switching elements are provided on a base substrate. A plurality of switching elements in the switching device are annularly arranged, and each switching element has a fixed portion joined to the base substrate, a movable portion extending from the fixed portion and extending along the base substrate, and a base substrate in the movable portion A movable signal electrode provided on the opposite side of the first fixed signal electrode, a first fixed signal electrode and a second fixed signal electrode each having a portion facing the movable signal electrode and each of which is joined to the fixed portion; A movable drive electrode provided on the opposite side of the base substrate from the base substrate, and a fixed drive electrode having a portion facing the movable drive electrode and joined to the fixed portion. The first fixed signal electrode of each first switching element constitutes an input terminal. The first fixed signal electrode of each second switching element constitutes an output terminal. The second fixed signal electrodes of the plurality of switching elements are electrically connected by a common wiring pattern.

  In this switching device, the plurality of first fixed signal electrodes in the plurality of first switching elements are the plurality of input terminals of the device, and the plurality of first fixed signal electrodes in the plurality of second switching elements are the devices of the device. A plurality of output terminals, for example, a multi-channel capable of selecting one channel is configured between the plurality of input terminals and the plurality of output terminals. A predetermined driving voltage is applied between the fixed driving electrode and the movable driving electrode of the selected first switching element, and the fixed driving electrode and the movable driving of the selected second switching element are applied. By applying a predetermined drive voltage between the electrodes, an input terminal formed by the first fixed signal electrode of the first switching element and an output terminal formed by the first fixed signal electrode of the second switching element When electrically connected (the second fixed signal electrodes of both selected switching elements are electrically connected by the common wiring pattern), the first and second switching elements are turned on, and the first Other combinations of the first and second switching elements are turned off.

  In the present switching device, the common wiring pattern for connecting the second fixed signal electrodes of the plurality (m) of first switching elements and the second fixed signal electrodes of the plurality (n) of second switching elements. , There are m × n conductive paths, a first switching element group having a first fixed signal electrode as an input terminal of the device, and a second having a first fixed signal electrode as an output terminal of the device. The configuration in which the switching element group is arranged so as to form one ring (for example, an annular ring) shortens and equalizes the length of m × n conductive paths while reducing the size of the device. Suitable for planning. And the shorter the conductive path between the switching elements, the lower the loss of the signal passing through the device. Therefore, this switching device is suitable for downsizing and low loss.

  In the second aspect of the present invention, preferably, the common wiring pattern has a central land portion and a communication pattern that connects the central land portion and the second fixed signal electrode of each switching element. Such a configuration is suitable for shortening and equalizing the length of the plurality of conductive paths between the plurality of first switching elements and the plurality of second switching elements.

  According to a third aspect of the present invention, there is provided another switching device in which a plurality of first switching elements and a plurality of second switching elements are provided on a base substrate. The plurality of switching elements in the switching device are annularly arranged, and each switching element includes a fixed portion joined to the base substrate, a movable land portion, and a first beam that connects between the movable land portion and the fixed portion. A movable portion extending along the base substrate from the fixed portion toward the outside of the annular arrangement, and a movable signal electrode provided on a side of the movable land portion opposite to the base substrate. A fixed signal electrode having a portion facing the movable signal electrode and joined to the fixed portion, a movable drive electrode provided on the side of the movable land portion opposite to the base substrate, and opposed to the movable drive electrode A fixed drive electrode having a portion and bonded to the fixed portion. The fixed signal electrode of each first switching element constitutes an input terminal. The fixed signal electrode of each second switching element constitutes an output terminal. The movable signal electrodes of the plurality of switching elements are electrically connected by a common wiring pattern having a portion that passes over the first beam portion of each switching element.

  In this switching device, the plurality of fixed signal electrodes in the plurality of first switching elements are the plurality of input terminals of the device, and the plurality of fixed signal electrodes in the plurality of second switching elements are the plurality of output terminals of the device. For example, a multi-channel capable of selecting one channel is configured between the plurality of input terminals and the plurality of output terminals. A predetermined driving voltage is applied between the fixed driving electrode and the movable driving electrode of the selected first switching element, and the fixed driving electrode and the movable driving of the selected second switching element are applied. By applying a predetermined drive voltage between the electrodes, the input terminal formed by the fixed signal electrode of the first switching element and the output terminal formed by the fixed signal electrode of the second switching element are electrically connected. (The movable signal electrodes of both selected switching elements are electrically connected by a common wiring pattern), the first and second switching elements are turned on, and the first and second switching elements are turned on. Other combinations of elements are turned off.

  In the present switching device, in the common wiring pattern for connecting the movable signal electrodes of the plurality (m) of first switching elements and the movable signal electrodes of the plurality (n) of second switching elements, m × n When there are two conductive paths, a first switching element group having a fixed signal electrode as an input terminal of the device and a second switching element group having a fixed signal electrode as an output terminal of the device are The configuration arranged to form a ring (for example, a ring) is suitable for shortening and uniformizing the length of m × n conductive paths while reducing the size of the apparatus. And the shorter the conductive path between the switching elements, the lower the loss of the signal passing through the device. Therefore, this switching device is suitable for downsizing and low loss.

  In the third aspect of the present invention, the movable signal electrode is arranged on the inner side in the annular arrangement than the movable drive electrode. Such a configuration is suitable for shortening the length of the plurality of conductive paths between the plurality of first switching elements and the plurality of second switching elements.

  Preferably, the common wiring pattern has a central land portion and a communication pattern that connects the central land portion and the movable signal electrode of each switching element. Such a configuration is suitable for shortening and equalizing the length of the plurality of conductive paths between the plurality of first switching elements and the plurality of second switching elements.

  In the second and third aspects of the present invention, preferably, the fixed drive electrodes of the plurality of switching elements are shared. Such a configuration is suitable for reducing the size of the apparatus.

  In the first to third aspects of the present invention, the number of the plurality of first switching elements and the plurality of second switching elements is five or more in total.

  In the fourth aspect of the present invention, preferably, the movable signal electrode is disposed closer to the first and second beam portions than the movable drive electrode.

  According to a fifth aspect of the present invention, a communication device is provided. The communication device selects a plurality of RF circuits, a plurality of antennas, and one of the plurality of RF circuits, and selects one of the plurality of antennas to connect the RF circuit and the antenna. Therefore, any one of the switching devices according to the first to third aspects is provided.

  FIG. 1 is a plan view of a switching device X1 according to the first embodiment of the present invention. The switching device X1 includes a plurality of switching elements Y, a common wiring pattern W, and bumps B that are integrally provided on a base substrate.

  3 to 7 show a single switching element Y constituting the switching device X1. 3 is a plan view of the switching element Y, and FIG. 4 is a partially omitted plan view of the switching element Y. 5 to 7 are sectional views taken along lines VV, VI-VI, and VII-VII in FIG. 3, respectively.

  The switching element Y includes a fixed portion 11, a movable portion 12, a signal electrode 13, a pair of signal electrodes 14 (represented by virtual lines in FIG. 4), a drive electrode 15, and a drive electrode 16 (virtual lines in FIG. 4). And).

  As shown in FIGS. 5 to 7, the fixing part 11 is bonded to the base substrate S via the boundary layer 17. The fixing portion 11 is made of a silicon material such as single crystal silicon. The silicon material constituting the fixing portion 11 preferably has a resistivity of 1000 Ω · cm or more. The boundary layer 17 is made of, for example, silicon dioxide.

For example, as shown in FIG. 4 or FIG. 7, the movable portion 12 extends from the fixed portion 11, extends along the base substrate S, and is surrounded by the fixed portion 11 via the slit 18. The thickness T ₁ shown in FIGS. 5 and 6 for the movable portion 12 is, for example, 15 μm or less. Further, the movable portion 12, the length L ₁ shown in FIG. 4 is a 650~1000μm example, the length L ₂ is 200~400μm example. The width of the slit 18 is, for example, 1.5 to 2.5 μm. The movable part 12 is made of, for example, single crystal silicon.

  The signal electrode 13 is a movable signal electrode and is provided near the free end of the movable part 12 on the side opposite to the base substrate S in the movable part 12 as shown in FIG. The thickness of the signal electrode 13 is, for example, 0.5 to 2 μm. The signal electrode 13 is made of a predetermined conductive material and has, for example, a laminated structure including a Mo base film and an Au film thereon.

  Each of the pair of signal electrodes 14 is a fixed signal electrode, and has a portion that stands on the fixed portion 11 and faces the signal electrode 13 as shown in FIG. In a portion facing the signal electrode 13, the signal electrode 14 has a protrusion 14a. As a constituent material of the signal electrode 14, Au can be adopted.

  The drive electrode 15 is a movable drive electrode, and is provided on the side of the movable portion 12 opposite to the base substrate S, as clearly shown in FIG. The thickness of the drive electrode 15 is, for example, 0.5 to 2 μm. As the constituent material of the drive electrode 15, the same constituent material as that of the signal electrode 13 can be employed. The drive electrode 15 is electrically connected to a wiring pattern 19 provided over the fixed portion 11 and the movable portion 12.

  The drive electrode 16 is a fixed drive electrode for generating an electrostatic attractive force (drive force) between the drive electrode 15, and as shown in FIG. 6, both ends thereof are fixed portions 11. And is erected so as to straddle the upper side of the drive electrode 15. The thickness of the drive electrode 16 is, for example, 15 μm or more. As the constituent material of the drive electrode 16, the same material as that of the signal electrode 14 can be employed.

  When a potential is applied to the drive electrode 15 in the switching element Y, an electrostatic attractive force is generated between the drive electrodes 15 and 16. When the applied potential is sufficiently high, the movable portion 12 operates or elastically deforms until the signal electrode 13 comes into contact with the protruding portion 14a of the signal electrode 14, as shown in FIG. In this way, the closed state of the switching element Y is achieved. In the closed state, the pair of signal electrodes 14 are electrically bridged by the signal electrodes 13, and current or high frequency signals are allowed to pass between the signal electrodes 14.

  On the other hand, in the switching element Y in the closed state, when the electrostatic attraction acting between the drive electrodes 15 and 16 is extinguished by stopping the potential application to the drive electrode 15, the movable portion 12 returns to its natural state. The signal electrode 13 is separated from the protrusion 14 a of the signal electrode 14. In this way, the open state of the switching element Y as shown in FIGS. 5 and 7 is achieved. In the open state, the pair of signal electrodes 14 are electrically separated, and current or high-frequency signals are prevented from passing between the signal electrodes 14. Further, the switching element Y in such an open state can be switched again to the closed state or the on state by the switch-on operation described above.

  The switching device X1 includes a configuration in which the five switching elements Y having the above configuration are substantially integrated. The five switching elements Y are composed of two switching elements Y1 and three switching elements Y2.

  Two switching elements Y1 are arranged in parallel, and one signal electrode 14 of each switching element Y1 constitutes an input terminal of the switching device X1. Further, the drive electrode 16 of the switching element Y1 is shared. These drive electrodes 16 are grounded, for example.

  On the other hand, the three switching elements Y2 form a line in the same direction as the arrangement direction of the switching elements Y1. One signal electrode 14 of each switching element Y2 constitutes an output terminal of the switching device X1. Further, the drive electrode 16 of the switching element Y2 is shared. These drive electrodes 16 are grounded, for example.

  The common wiring pattern W is arranged between the first column formed by the switching element Y1 and the second column formed by the switching element Y2, and extends along the first and second columns. And a branch pattern Wb that connects the stem pattern Wa and one signal electrode 14 of each of the switching elements Y1, Y2. Through such a common wiring pattern W, one signal electrode 14 of all the switching elements Y1, Y2 is electrically connected.

  Bump B is a flip-chip mounting bump, and is fixed to one signal electrode 14 of each switching element Y, wiring pattern 19 connected to drive electrode 15, and drive electrode 16. The switching device X1 is electrically connected to an external circuit via the bump B.

  In the switching device X1, the two signal electrodes 14 in the two switching elements Y1 are the two input terminals of the device, and the three signal electrodes 14 in the three switching elements Y2 are the three of the device. For example, a multi-channel capable of selecting one channel is configured between the two input terminals and the three output terminals. Then, a predetermined drive voltage is applied between the drive electrodes 15 and 16 of the selected one switching element Y1, and a predetermined drive voltage is applied between the drive electrodes 15 and 16 of the selected one switching element Y2. By doing so, one signal electrode 14 (input terminal) of the switching element Y1 and one signal electrode 14 (output terminal) of the switching element Y2 are electrically connected, and the switching elements Y1 and Y2 are connected. Is turned on, and other combinations of the switching elements Y1 and Y2 are turned off. In the switching device X1, in this way, for example, an on state of a high-frequency signal can be achieved between the selected switching elements Y1 and Y2.

  In the switching device X1, there are 2 × 3 conductive paths in the common wiring pattern W that connects between one signal electrode 14 of the two switching elements Y1 and one signal electrode 14 of the three switching elements Y2. Where present (one conductive path is indicated by a broken line in FIG. 1), a switching element Y1 group having a signal electrode 14 as an input terminal of the device, and a switching element Y2 group having a signal electrode 14 as an output terminal of the device; However, the configuration in which each is arranged in a row and opposed to each other via the common wiring pattern W is intended to shorten and equalize the length of the 2 × 3 conductive paths while reducing the size of the device. Suitable for And the shorter the conductive path between the elements, the lower the loss of signal passing through the device. Therefore, the switching device X1 is suitable for downsizing and low loss.

  As described above, the common wiring pattern W of the switching device X1 includes the stem pattern Wa extending along the row between the first row formed by the switching element Y1 and the second row formed by the switching element Y2, and The branch pattern Wb that connects the stem pattern Wa and one signal electrode 14 of each of the switching elements Y1 and Y2 is provided. Such a configuration is provided between the two switching elements Y1 and the three switching elements Y2. This contributes to shortening and equalizing the length of the plurality of conductive paths.

  In the switching device X1, as described above, the drive electrodes 16 of the plurality of switching elements Y1 are shared and the drive electrodes 16 of the plurality of switching elements Y2 are shared. Contributes to downsizing.

  In the switching device X1, the number of switching elements Y1 is not limited to 2, the number of switching elements Y2 is not limited to 3, and the total number of switching elements Y is not limited to 5. These numbers are changed as necessary in accordance with the circuit or system to which the switching device X1 is connected.

  9 to 12 show a method of manufacturing each switching element Y included in the switching device X1 as a change in cross section corresponding to FIGS. 5 and 6. In this method, first, a material substrate 100 as shown in FIG. 9A is prepared. The material substrate 100 is an SOI (silicon on insulator) substrate and has a stacked structure including a first layer 101, a second layer 102, and an intermediate layer 103 therebetween. In the present embodiment, for example, the thickness of the first layer 101 is 15 μm, the thickness of the second layer 102 is 525 μm, and the thickness of the intermediate layer 103 is 4 μm. The first layer 101 is made of, for example, single crystal silicon, and is processed into the above-described fixed portion 11 and movable portion 12. The second layer 102 is made of, for example, single crystal silicon and serves as the base substrate S described above. The intermediate layer 103 is made of, for example, silicon dioxide, and is processed into the boundary layer 17 described above.

  Next, as illustrated in FIG. 9B, a conductor film 104 is formed on the first layer 101. For example, Mo is deposited on the first layer 101 by sputtering, and then Au is deposited thereon. The thickness of the Mo film is, for example, 30 nm, and the thickness of the Au film is, for example, 500 nm.

  Next, as shown in FIG. 9C, resist patterns 105 and 106 are formed on the conductor film 104 by photolithography. The resist pattern 105 has a pattern shape corresponding to the signal electrode 13 described above. The resist pattern 106 has a pattern shape corresponding to the drive electrode 15 and the wiring pattern 19 described above.

  Next, as shown in FIG. 10A, the conductor film 104 is etched using the resist patterns 105 and 106 as a mask. As a result, the signal electrode 13, the drive electrode 15, and the wiring pattern 19 are formed outside the drawing on the first layer 101. As an etching method in this step, ion milling (for example, physical etching with Ar ions) can be employed. Ion milling can also be employed as an etching method for the metal materials described later.

  Next, after the resist patterns 105 and 106 are removed, as shown in FIG. 10B, the first layer 101 is etched to form the slits 18. Specifically, after a predetermined resist pattern is formed on the first layer 101 by a photolithography method, anisotropic etching is performed on the first layer 101 using the resist pattern as a mask. As an etching method, reactive ion etching can be employed. In this step, the fixed portion 11 and the movable portion 12 are patterned.

  Next, as illustrated in FIG. 10C, a sacrificial layer 107 is formed on the first layer 101 side of the material substrate 100 so as to close the slit 18. For example, silicon dioxide can be used as the sacrificial layer material. Further, as a method for forming the sacrificial layer 107, for example, a plasma CVD method or a sputtering method can be employed.

  Next, as shown in FIG. 11A, a recess 107 a is formed at a location corresponding to the signal electrode 13 in the sacrificial layer 107. Specifically, after a predetermined resist pattern is formed on the sacrificial layer 107 by a photolithography method, the sacrificial layer 107 is etched using the resist pattern as a mask. As an etching method, wet etching can be employed. As an etchant for wet etching, for example, buffered hydrofluoric acid (BHF) can be employed. BHF can also be employed in the later wet etching for the sacrificial layer 107. The recess 107a is for forming the projection 14a of each signal electrode 14. The distance between the bottom surface of the recess 107a and the signal electrode 13 is, for example, 2 μm or less.

  Next, as shown in FIG. 11B, the sacrifice layer 107 is patterned to form openings 107b and 107c. Specifically, after a predetermined resist pattern is formed on the sacrificial layer 107 by a photolithography method, the sacrificial layer 107 is etched using the resist pattern as a mask. As an etching method, wet etching can be employed. Each of the openings 107b is for exposing a region where the signal electrode 14 is joined in the fixed portion 11. The opening 107c is for exposing a region where the drive electrode 16 is joined in the fixed portion 11.

  Next, after a base film (not shown) for energization is formed on the surface of the material substrate 100 where the sacrificial layer 107 is provided, a resist pattern 108 is formed as shown in FIG. The base film can be formed, for example, by depositing Mo with a thickness of 50 nm by sputtering and then depositing Au with a thickness of 500 nm thereon. The resist pattern 108 has an opening 108 a corresponding to each signal electrode 14 and an opening 108 b corresponding to the drive electrode 16.

  Next, as shown in FIG. 12A, the signal electrodes 14 and the drive electrodes 16 are formed. Specifically, for example, Au is grown by electroplating on the above-described base film exposed at the openings 108a and 108b.

  Next, as shown in FIG. 12B, the resist pattern 108 is removed by etching. Thereafter, the exposed portion of the base film for electroplating is removed by etching. In these etching removals, wet etching can be employed.

  Next, as shown in FIG. 12C, the sacrificial layer 107 and a part of the intermediate layer 103 are removed. Specifically, wet etching is performed on the sacrificial layer 107 and the intermediate layer 103. In this etching process, the sacrificial layer 107 is first removed, and then a part of the intermediate layer 103 is removed from the portion facing the slit 18. This etching process stops after an appropriate gap is formed between the entire movable portion 12 and the second layer 102. In this way, the boundary layer 17 remains in the intermediate layer 103. The second layer 102 constitutes the base substrate S.

  Next, if necessary, after removing a part of the base film (for example, Mo film) adhering to the lower surfaces of each signal electrode 14 and drive electrode 16 by wet etching, the entire element is dried by a supercritical drying method. To do. According to the supercritical drying method, the sticking phenomenon that the movable part 12 sticks to the base substrate S or the like can be appropriately avoided.

  As described above, each switching element Y included in the switching device X1 can be manufactured. In this method, the pair of signal electrodes 14 having portions facing the signal electrodes 13 can be formed thick on the sacrificial layer 107 by plating. Therefore, it is possible to set a sufficient thickness for realizing a desired low resistance for the pair of signal electrodes 14. The thick signal electrode 14 is preferable for reducing the insertion loss of the switching element Y.

  FIG. 13 is a plan view of a switching device X2 according to the second embodiment of the present invention. The switching device X2 includes a plurality of switching elements Y, a common wiring pattern W ′, and bumps B that are integrally provided on a base substrate.

  The switching device X2 includes a configuration in which 13 switching elements Y having the configuration described above with reference to FIGS. 3 to 7 are substantially integrated. The thirteen switching elements Y are composed of three switching elements Y1 and ten switching elements Y2, and are arranged in an annular shape. One signal electrode 14 of each switching element Y1 constitutes an input terminal of the switching device X2. One signal electrode 14 of each switching element Y2 constitutes an output terminal of the switching device X2. Further, the drive electrodes 16 of the switching elements Y1, Y2 are shared. These drive electrodes 16 are grounded, for example.

  The common wiring pattern W ′ has a central land portion Wc and a communication pattern Wd that connects the central land portion Wc and one signal electrode 14 of each of the switching elements Y1, Y2. The plurality of contact patterns Wd extend radially. One signal electrode 14 of all the switching elements Y1, Y2 is electrically connected through such a common wiring pattern W '.

  Bump B is a flip-chip mounting bump, and is fixed to one signal electrode 14 of each switching element Y, wiring pattern 19 connected to drive electrode 15, and drive electrode 16. The switching device X2 is electrically connected to an external circuit via the bump B.

  In the switching device X2, the three signal electrodes 14 in the three switching elements Y1 are the three input terminals of the present device, and the ten signal electrodes 14 in the ten switching elements Y2 are the ten of the device. For example, a multi-channel capable of selecting one channel is configured between the three input terminals and the ten output terminals. Then, a predetermined drive voltage is applied between the drive electrodes 15 and 16 of the selected one switching element Y1, and a predetermined drive voltage is applied between the drive electrodes 15 and 16 of the selected one switching element Y2. By doing so, one signal electrode 14 (input terminal) of the switching element Y1 and one signal electrode 14 (output terminal) of the switching element Y2 are electrically connected, and the switching elements Y1 and Y2 are connected. Is turned on, and other combinations of the switching elements Y1 and Y2 are turned off. In the switching device X2, in this way, for example, an on state of a high-frequency signal can be achieved between the selected switching elements Y1 and Y2.

  In the switching device X2, there are 3 × 10 conductive paths in the common wiring pattern W ′ that connects between one signal electrode 14 of the three switching elements Y1 and one signal electrode 14 of the ten switching elements Y2. (One conductive path is indicated by a broken line in FIG. 13), a switching element Y1 group having a signal electrode 14 as an input terminal of the device and a switching element Y2 group having a signal electrode 14 as an output terminal of the device However, the arrangement arranged in an annular shape is suitable for shortening and equalizing the length of the 3 × 10 conductive paths while reducing the size of the apparatus. And the shorter the conductive path between the elements, the lower the loss of signal passing through the device. Therefore, the switching device X2 is suitable for reducing the size and the loss.

  As described above, the common wiring pattern W ′ of the switching device X2 includes the central land portion Wc and the contact pattern Wd that connects the central land portion Wc and one signal electrode 14 of each of the switching elements Y1 and Y2. However, such a configuration shortens or equalizes the lengths of the plurality of conductive paths between the three switching elements Y1 and the ten switching elements Y2 that are arranged in a ring shape. Contribute to

  In the switching device X2, as described above, the drive electrodes 16 of all the switching elements Y are shared, but this configuration contributes to downsizing of the device.

  In the switching device X2, the number of switching elements Y1 is not limited to 3, the number of switching elements Y2 is not limited to 10, and the total number of switching elements Y is not limited to 13. These numbers are changed as necessary in accordance with the circuit or system to which the switching device X2 is connected.

  FIG. 15 is a plan view of a switching device X3 according to the third embodiment of the present invention. The switching device X3 includes a plurality of switching elements Z, a common wiring pattern W ′, and bumps B that are integrally provided on the base substrate.

  17 to 21 show a single switching element Z that constitutes the switching device X3. 17 is a plan view of the switching element Z, and FIG. 18 is a partially omitted plan view of the switching element Z. 19 to 21 are cross-sectional views taken along line XIX-XIX, line XX-XX, and line XXI-XXI in FIG. 17, respectively.

  The switching element Z includes a fixed portion 21, a movable portion 22, a signal electrode 23, a signal electrode 24 (represented by a virtual line in FIG. 18), a drive electrode 25, and a drive electrode 26 (represented by a virtual line in FIG. 18). ).

  As shown in FIGS. 19 to 21, the fixing portion 21 is bonded to the base substrate S via the boundary layer 27. The fixing portion 21 is made of a silicon material such as single crystal silicon. It is preferable that the silicon material constituting the fixing portion 21 has a resistivity of 1000 Ω · cm or more. The boundary layer 27 is made of, for example, silicon dioxide.

For example, as shown in FIG. 18 or FIG. 21, the movable portion 22 extends from the fixed portion 21, extends along the base substrate S, and is surrounded by the fixed portion 21 through the slit 28. The movable portion 22 includes a land portion 22a and beam portions 22b and 22c that connect the land portion 22a and the fixed portion 21 in parallel. The thickness T ₂ shown in FIGS. 19 and 20 for the movable portion 22 is, for example, 25 μm or less. Further, the movable portion 22, the length L ₃ shown in FIG. 18 is a 650~1000μm example, the length L ₄ represents a 200~400μm example. The width of the slit 28 is, for example, 1.5 to 2.5 μm. The movable part 22 is made of, for example, single crystal silicon.

  The signal electrode 23 is a movable signal electrode, and as shown well in FIG. It is provided near. The thickness of the signal electrode 23 is, for example, 0.5 to 2 μm. The signal electrode 23 is made of a predetermined conductive material and has, for example, a laminated structure including a Mo base film and an Au film thereon. The signal electrode 23 is electrically connected to a predetermined wiring pattern having a portion that passes over the beam portion 22 b of the movable portion 22.

  The signal electrode 24 is a fixed signal electrode, and has a portion that is erected on the fixed portion 21 and faces the signal electrode 23 as shown in FIG. 19 or FIG. In a portion facing the signal electrode 23, the signal electrode 24 has a protrusion 24a. As a constituent material of the signal electrode 24, Au can be adopted.

  The drive electrode 25 is a movable drive electrode, and is provided near the free end of the movable portion 22 on the side opposite to the base substrate S in the land portion 22a of the movable portion 22 as shown in FIG. ing. The thickness of the drive electrode 25 is, for example, 0.5 to 2 μm. As the constituent material of the drive electrode 25, the same constituent material as that of the signal electrode 23 can be employed. The drive electrode 25 has a portion passing over the beam portion 22 c of the movable portion 22 and is electrically connected to a wiring pattern 29 provided over the movable portion 22 and the fixed portion 21.

  The drive electrode 26 is a fixed drive electrode, and is for generating an electrostatic attractive force (drive force) between the drive electrode 25. As shown well in FIG. And is erected so as to straddle the upper side of the drive electrode 25. The thickness of the drive electrode 26 is, for example, 10 μm or more. As the constituent material of the drive electrode 26, the same constituent material as that of the signal electrode 24 can be employed.

  In the switching element Z, when a potential is applied to the drive electrode 25, an electrostatic attractive force is generated between the drive electrodes 25 and 26. When the applied potential is sufficiently high, the movable portion 22 operates or elastically deforms until the signal electrode 23 comes into contact with the protruding portion 24a of the signal electrode 24 as shown in FIG. In this way, the closed state of the switching element Z is achieved. In the closed state, the signal electrodes 23 and 24 are electrically connected, and a current or a high-frequency signal is allowed to pass between the signal electrodes 23 and 24.

  On the other hand, in the switching element Z in the closed state, when the electrostatic attraction acting between the drive electrodes 25 and 26 is extinguished by stopping the potential application to the drive electrode 25, the movable portion 22 returns to its natural state. The signal electrode 23 is separated from the protrusion 24 a of the signal electrode 24. In this way, the open state of the switching element Z as shown in FIGS. 19 and 21 is achieved. In the open state, the signal electrodes 23 and 24 are electrically separated, and current or high frequency signals are prevented from passing between the signal electrodes 23 and 24. Further, the switching element Z in such an open state can be switched again to the closed state or the on state by the switch-on operation described above.

  The switching device X3 includes a configuration in which 13 switching elements Z having the above configuration are substantially integrated. The thirteen switching elements Z are composed of three switching elements Z1 and ten switching elements Z2, and are arranged in an annular shape. The signal electrode 24 of each switching element Z1 constitutes an input terminal of the switching device X3. The signal electrode 24 of each switching element Z2 constitutes an output terminal of the switching device X3. Further, the drive electrodes 26 of the switching elements Z1, Z2 are shared. These drive electrodes 26 are grounded, for example.

  The common wiring pattern W 'has a central land portion Wc and a communication pattern Wd that connects the central land portion Wc and the signal electrodes 23 of the switching elements Z1 and Z2. The connection pattern Wd has a portion that passes over the beam portion 22 b of the movable portion 22. The plurality of contact patterns Wd extend radially. The signal electrodes 23 of all the switching elements Z1, Z2 are electrically connected through such a common wiring pattern W '.

  The bump B is a flip chip mounting bump, and is fixed to the signal electrode 24 of each switching element Z, the wiring pattern 29 connected to the drive electrode 25, and the drive electrode 26. The switching device X3 is electrically connected to an external circuit via the bump B.

  In the switching device X3, the three signal electrodes 24 in the three switching elements Z1 are the three input terminals of the present device, and the ten signal electrodes 24 in the ten switching elements Z2 are the ten of the device. For example, a multi-channel capable of selecting one channel is configured between the three input terminals and the ten output terminals. Then, a predetermined drive voltage is applied between the drive electrodes 25 and 26 of the selected one switching element Z1, and a predetermined drive voltage is applied between the drive electrodes 25 and 26 of the selected one switching element Z2. As a result, the signal electrode 24 (input terminal) of the switching element Z1 and the signal electrode 24 (output terminal) of the switching element Z2 are electrically connected, and the switching elements Z1 and Z2 are turned on. The other combinations of the switching elements Z1 and Z2 are turned off. In the switching device X3, for example, an on state of a high-frequency signal can be achieved between the selected switching elements Z1 and Z2.

  In the switching device X3, there are 3 × 10 conductive paths in the common wiring pattern W ′ that connects between the signal electrodes 23 of the three switching elements Z1 and the signal electrodes 23 of the ten switching elements Z2. A switching element Z1 group having a signal electrode 24 as an input terminal of the device and a switching element Z2 group having a signal electrode 24 as an output terminal of the device are circular (one conductive path is indicated by a broken line in FIG. 15). The arrangement arranged in a ring is suitable for shortening and equalizing the length of 3 × 10 conductive paths while reducing the size of the apparatus. And the shorter the conductive path between the elements, the lower the loss of signal passing through the device. Therefore, the switching device X3 is suitable for reducing the size and the loss.

  As described above, the common wiring pattern W ′ of the switching device X3 has the central land portion Wc and the contact pattern Wd that connects the central land portion Wc and the signal electrodes 23 of the switching elements Z1 and Z2. Such a configuration is used to shorten or equalize the length of the plurality of conductive paths between the three switching elements Z1 and the ten switching elements Z2 arranged in a ring shape. To contribute.

  In the switching device X3, as described above, the drive electrodes 26 of all the switching elements Z are shared, but such a configuration contributes to downsizing of the device.

  In the switching device X3, the signal electrode 23 connected to the connection pattern Wd of the common wiring pattern W ′ on the movable portion 22 is located on the inner side in the annular arrangement of elements (that is, the common wiring pattern W ′ In this configuration, the length of the plurality of conductive paths between the three switching elements Z1 and the ten switching elements Z2 is shortened. Contribute to

  In the switching device X3, the number of switching elements Z1 is not limited to 3, the number of switching elements Z2 is not limited to 10, and the total number of switching elements Z is not limited to 13. These numbers are changed as necessary in accordance with the circuit or system to which the switching device X3 is connected.

  FIG. 23 shows a partial configuration of a communication device 200 according to the fourth embodiment of the present invention. The communication device 200 includes a plurality of RF circuits C1 to Cm, a plurality of antennas A1 to Am, and an mPmT type switching device 201 between them, and is configured as a mobile phone, for example.

  Each of the plurality of RF circuits C1 to Cm is a duplexer in the present embodiment, includes an LNA, a PA, and the like, and is connected to the baseband. Each of the RF circuits C1 to Cm is provided for each frequency band used by the communication device 200 for transmission and reception. The plurality of antennas A <b> 1 to Am have different directivities, and are provided in order to obtain a better reception state in the communication device 200.

  The switching device 201 is for switching the connection relationship between the plurality of RF circuits C1 to Cm and the plurality of antennas A1 to Am according to the communication frequency, and is configured by any one of the switching devices X1 to X3 described above. Has been. Specifically, the switching device 201 selects one of the plurality of RF circuits C1 to Cm and selects one of the plurality of antennas A1 to Am having the best reception state, and selects the selected RF. The channel between the circuit and the selected antenna can be turned on.

  By including the plurality of RF circuits C1 to Cm, the plurality of antennas A1 to Am, and the switching device 201 as described above, the communication device 200 can be a multiband capable of supporting a plurality of systems of different frequency bands. It can operate as a communication device.

  As a summary of the above, the configurations of the present invention and variations thereof are listed below as supplementary notes.

(Appendix 1) A switching device in which a plurality of first switching elements and a plurality of second switching elements are provided on a base substrate,
Each switching element
A fixing portion bonded to the base substrate;
A movable part extending from the fixed part and extending along the base substrate;
A movable signal electrode provided on the side of the movable part opposite to the base substrate;
A first fixed signal electrode and a second fixed signal electrode each having a portion facing the movable signal electrode and each of which is joined to the fixed portion;
A movable drive electrode provided on the side of the movable part opposite to the base substrate;
A fixed drive electrode having a portion facing the movable drive electrode and joined to the fixed portion,
The plurality of first switching elements form a first column, and the first fixed signal electrode of each first switching element constitutes an input terminal;
The plurality of second switching elements form a second column extending along the first column, and the first fixed signal electrode of each second switching element constitutes an output terminal,
The switching device, wherein the second fixed signal electrodes of the plurality of switching elements are electrically connected by a common wiring pattern arranged between the first and second columns.
(Supplementary Note 2) The common wiring pattern includes a first pattern extending along the column between the first and second columns, and the second fixed signal electrode of the first pattern and each switching element. The switching device according to appendix 1, having a second pattern for communicating
(Supplementary note 3) The switching device according to supplementary note 1 or 2, wherein the fixed drive electrodes of the plurality of first switching elements are shared.
(Supplementary note 4) The switching device according to any one of supplementary notes 1 to 3, wherein the fixed drive electrodes of the plurality of second switching elements are shared.
(Supplementary Note 5) A switching device in which a plurality of first switching elements and a plurality of second switching elements are provided on a base substrate,
The plurality of switching elements are annularly arranged,
Each switching element
A fixing portion bonded to the base substrate;
A movable part extending from the fixed part and extending along the base substrate;
A movable signal electrode provided on the side of the movable part opposite to the base substrate;
A first fixed signal electrode and a second fixed signal electrode each having a portion facing the movable signal electrode and each of which is joined to the fixed portion;
A movable drive electrode provided on the side of the movable part opposite to the base substrate;
A fixed drive electrode having a portion facing the movable drive electrode and joined to the fixed portion,
The first fixed signal electrode of each first switching element constitutes an input terminal;
The first fixed signal electrode of each second switching element constitutes an output terminal;
The switching device, wherein the second fixed signal electrodes of the plurality of switching elements are electrically connected by a common wiring pattern.
(Supplementary note 6) The switching device according to supplementary note 5, wherein the common wiring pattern has a central land portion and a communication pattern that connects the central land portion and the second fixed signal electrode of each switching element.
(Appendix 7) A switching device in which a plurality of first switching elements and a plurality of second switching elements are provided on a base substrate,
The plurality of switching elements are annularly arranged,
Each switching element
A fixing portion bonded to the base substrate;
A movable land portion, and a first beam portion and a second beam portion connecting between the movable land portion and the fixed portion, and along the base substrate from the fixed portion toward the outside of the annular arrangement. A movable part that extends,
A movable signal electrode provided on a side of the movable land portion opposite to the base substrate;
A fixed signal electrode having a portion facing the movable signal electrode and joined to the fixed portion;
A movable drive electrode provided on the side of the movable land portion opposite to the base substrate;
A fixed drive electrode having a portion facing the movable drive electrode and joined to the fixed portion,
The fixed signal electrode of each first switching element constitutes an input terminal;
The fixed signal electrode of each second switching element constitutes an output terminal;
The switching device, wherein the movable signal electrodes of the plurality of switching elements are electrically connected by a common wiring pattern having a portion passing over the first beam portion of each switching element.
(Supplementary note 8) The switching device according to supplementary note 7, wherein the movable signal electrode is arranged on an inner side in the annular arrangement than the movable drive electrode.
(Supplementary note 9) The switching device according to supplementary note 7 or 8, wherein the common wiring pattern has a central land portion and a communication pattern that connects the central land portion and the movable signal electrode of each switching element.
(Supplementary note 10) The switching device according to any one of supplementary notes 5 to 9, wherein the fixed drive electrodes of the plurality of switching elements are shared.
(Supplementary note 11) The switching device according to any one of claims 1 to 10, wherein the number of the plurality of first switching elements and the plurality of second switching elements is five or more in total.
(Additional remark 12) The fixed part joined to the base substrate and the base substrate,
A movable land portion, and a movable portion having a first beam portion and a second beam portion connecting between the movable land portion and the fixed portion, and extending along the base substrate;
A movable signal electrode provided on a side of the movable land portion opposite to the base substrate;
A fixed signal electrode having a portion facing the movable signal electrode and joined to the fixed portion;
A first wiring pattern having a portion passing over the first beam portion and electrically connected to the movable signal electrode;
A movable drive electrode provided on the side of the movable land portion opposite to the base substrate;
A fixed drive electrode having a portion facing the movable drive electrode and joined to the fixed portion;
A switching element comprising: a second wiring pattern having a portion passing over the second beam portion and electrically connected to the movable drive electrode.
(Supplementary note 13) The switching element according to supplementary note 12, wherein the movable signal electrode is arranged closer to the first and second beam portions than the movable drive electrode.
(Supplementary note 14) a plurality of RF circuits;
Multiple antennas,
Item 12. The appendix 1 to 11, wherein one of the plurality of RF circuits is selected and one of the plurality of antennas is selected to connect the RF circuit and the antenna. A switching device.

1 is a plan view of a switching device according to a first embodiment of the present invention. FIG. 2 is a partially omitted plan view of the switching device shown in FIG. 1. It is a top view of the switching element which comprises the switching apparatus shown in FIG. FIG. 4 is a partially omitted plan view of the switching element shown in FIG. 3. FIG. 5 is a cross-sectional view taken along line VV in FIG. 3. FIG. 4 is a cross-sectional view taken along line VI-VI in FIG. 3. FIG. 4 is a cross-sectional view taken along line VII-VII in FIG. 3. FIG. 4 is a cross-sectional view taken along line VII-VII in FIG. 3 in an on state. FIG. 4 shows some steps in the method of manufacturing the switching element shown in FIG. 3. The process following FIG. 9 is represented. The process following FIG. 10 is represented. The process following FIG. 11 is represented. It is a top view of a switching device concerning a 2nd embodiment of the present invention. FIG. 14 is a partially omitted plan view of the switching device shown in FIG. 13. It is a top view of a switching device concerning a 3rd embodiment of the present invention. FIG. 16 is a partially omitted plan view of the switching device shown in FIG. 15. It is a top view of the switching element which comprises the switching apparatus shown in FIG. FIG. 18 is a partially omitted plan view of the switching element shown in FIG. 17. FIG. 18 is a cross-sectional view taken along line XIX-XIX in FIG. 17. It is sectional drawing along line XX-XX of FIG. It is sectional drawing along line XXI-XXI of FIG. FIG. 18 is a cross-sectional view taken along line XXI-XXI in FIG. The partial structure of the communication apparatus which concerns on the 4th Embodiment of this invention is represented.

Explanation of symbols

X1, X2, X3 Switching device Y, Y1, Y2, Z, Z1, Z2 Switching element S Base substrate 11, 21 Fixed portion 12 Movable portion 13, 14, 23, 24 Signal electrode 14a, 24 Protrusion portion 15, 16, 25 , 26 Drive electrode 17, 27 Boundary layer 18, 28 Slit 19, 29 Wiring pattern 22 Movable part 22a Land part 22b, 22c Beam part W, W 'Common wiring pattern Wa Stem pattern Wb Branch pattern Wc Central land part Wd Connection pattern B Bump 200 Communication equipment C1 to Cm RF circuit A1 to Am Antenna 201 Switching device

Claims (7)

A switching device in which a plurality of first switching elements and a plurality of second switching elements are provided on a base substrate,
Each switching element
A fixing portion bonded to the base substrate;
A movable part extending from the fixed part and extending along the base substrate;
A movable signal electrode provided on the side of the movable part opposite to the base substrate;
A first fixed signal electrode and a second fixed signal electrode each having a portion facing the movable signal electrode and each of which is joined to the fixed portion;
A movable drive electrode provided on the side of the movable part opposite to the base substrate;
A fixed drive electrode having a portion facing the movable drive electrode and joined to the fixed portion,
The plurality of first switching elements form a first column, and the first fixed signal electrode of each first switching element constitutes an input terminal;
The plurality of second switching elements form a second column extending along the first column, and the first fixed signal electrode of each second switching element constitutes an output terminal,
The switching device, wherein the second fixed signal electrodes of the plurality of switching elements are electrically connected by a common wiring pattern arranged between the first and second columns.   The common wiring pattern includes a first pattern extending along the column between the first and second columns, and a first pattern that connects the first pattern and the second fixed signal electrode of each switching element. The switching device according to claim 1, having two patterns. A switching device in which a plurality of first switching elements and a plurality of second switching elements are provided on a base substrate,
The plurality of switching elements are annularly arranged,
Each switching element
A fixing portion bonded to the base substrate;
A movable part extending from the fixed part and extending along the base substrate;
A movable signal electrode provided on the side of the movable part opposite to the base substrate;
A first fixed signal electrode and a second fixed signal electrode each having a portion facing the movable signal electrode and each of which is joined to the fixed portion;
A movable drive electrode provided on the side of the movable part opposite to the base substrate;
A fixed drive electrode having a portion facing the movable drive electrode and joined to the fixed portion,
The first fixed signal electrode of each first switching element constitutes an input terminal;
The first fixed signal electrode of each second switching element constitutes an output terminal;
The switching device, wherein the second fixed signal electrodes of the plurality of switching elements are electrically connected by a common wiring pattern.   4. The switching device according to claim 3, wherein the common wiring pattern has a central land portion and a communication pattern that connects the central land portion and the second fixed signal electrode of each switching element. A switching device in which a plurality of first switching elements and a plurality of second switching elements are provided on a base substrate,
The plurality of switching elements are annularly arranged,
Each switching element
A fixing portion bonded to the base substrate;
A movable land portion, and a first beam portion and a second beam portion connecting between the movable land portion and the fixed portion, and along the base substrate from the fixed portion toward the outside of the annular arrangement. A movable part that extends,
A movable signal electrode provided on a side of the movable land portion opposite to the base substrate;
A fixed signal electrode having a portion facing the movable signal electrode and joined to the fixed portion;
A movable drive electrode provided on the side of the movable land portion opposite to the base substrate;
A fixed drive electrode having a portion facing the movable drive electrode and joined to the fixed portion,
The fixed signal electrode of each first switching element constitutes an input terminal;
The fixed signal electrode of each second switching element constitutes an output terminal;
The switching device, wherein the movable signal electrodes of the plurality of switching elements are electrically connected by a common wiring pattern having a portion passing over the first beam portion of each switching element.   The switching device according to claim 5, wherein the movable signal electrode is arranged inside the annular arrangement with respect to the movable drive electrode. A plurality of RF circuits;
Multiple antennas,
7. The method according to claim 1, wherein one of the plurality of RF circuits is selected and one of the plurality of antennas is selected to connect the RF circuit and the antenna. A communication device comprising the switching device described above.

Images