JP2007142854A - Signal transmission circuit device and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a signal transmission circuit device and its manufacturing method which reduces the dielectric loss of a signal transmission circuit at a low cost to improve its electric reliability. <P>SOLUTION: A thin film of ion-migrated Pyrex (R) glass 3 anodic-bonded to a silicon substrate 2 is provided between, e.g., a CPW 5 constituting a signal transmission circuit and the silicon substrate 2. Accordingly, a signal flowing in the CPW 5 reduces the dielectric loss resulting from the Pyrex (R) glass 3 and the silicon substrate 2. Since the Pyrex (R) glass 3 of a low cost is usable, compared with the quartz substrate; the circuit device 1 allows the cost to be down. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a signal transmission circuit device and a method for manufacturing the signal transmission circuit device.

  Conventionally, a MEMS (Micro Electro Mechanical Systems) such as a pressure sensor is formed on a semiconductor substrate made of silicon, and another substrate such as a glass substrate is joined so as to surround the MEMS, thereby producing a signal transmission circuit device or the like. Yes.

  However, there is a problem that the manufacturing process for electrical connection between the MEMS and the outside and the electrical reliability are not necessarily sufficient.

Therefore, for example, a diaphragm portion and a first electrode are provided on a semiconductor substrate, a glass substrate is bonded to the surface of the semiconductor substrate on the first electrode side, and the second electrode is positioned at a position facing the first electrode of the glass substrate. An electrode is provided, and a circuit part for calculating the pressure to be measured by the capacitance between the electrodes is provided on the surface of the semiconductor substrate on the glass substrate side, and a recess for wiring extraction is formed on the surface of the semiconductor substrate opposite to the glass substrate. In addition, an external extraction wiring is provided in the wiring extraction recess, and a diffusion layer for electrically connecting the external extraction wiring portion and the internal wiring portion connected to the circuit portion is provided in the semiconductor substrate. A pressure sensor has been proposed (see, for example, Patent Document 1).
JP-A-6-300651 (paragraph [0011], FIG. 2)

  However, the apparatus described in Patent Document 1 has a problem that a signal flowing through a circuit unit or an internal wiring unit is affected by dielectric loss from a semiconductor substrate or the like and attenuates. In particular, in a high-frequency circuit in MEMS, the influence cannot be ignored, and it has been required to solve the problem at low cost.

  In view of the circumstances as described above, an object of the present invention is to provide a signal transmission circuit device and a method for manufacturing the signal transmission circuit device that reduce the dielectric loss of the signal transmission circuit and improve its electrical reliability at a low cost. There is to do.

  In order to achieve the above object, a signal transmission circuit device according to the present invention includes a substrate, a signal transmission circuit provided on the substrate, and a substrate provided between the substrate and the signal transmission circuit. And an anodic bonded dielectric. Here, the “signal transmission circuit” includes, for example, a high-frequency circuit including a CPW (Co planar Waveguide), an antenna, a MEMS switch, an electrode, a coil, and the like.

  In the present invention, since the dielectric that is anodically bonded and ion-moved between the signal transmission circuit and the substrate is provided, the dielectric loss that the signal flowing through the signal transmission circuit receives from the dielectric and the substrate can be reduced. .

  According to an embodiment of the present invention, the substrate is a silicon substrate, and the dielectric is Pyrex (registered trademark) glass. Thereby, silicon generally used in a signal transmission circuit device can be used, and Na ions in Pyrex (registered trademark) glass can be used for anodic bonding. Further, Pyrex (registered trademark) glass has almost the same thermal expansion coefficient as that of silicon and facilitates anodic bonding and the like, and a signal transmission circuit device can be manufactured at low cost.

  According to an aspect of the present invention, the substrate is made of metal, and the dielectric is Pyrex (registered trademark) glass. Thus, Na ions in Pyrex (registered trademark) glass can be used for anodic bonding, and the substrate is made of metal, so that the degree of freedom in design can be improved. In addition, the metal can shield electromagnetic waves leaking from, for example, CPW.

  According to one form of this invention, the said metal consists of kovar. Accordingly, since the thermal expansion coefficient of Kovar is close to Pyrex (registered trademark) glass, anodic bonding can be performed stably and easily, and a signal transmission circuit device can be manufactured at low cost.

  According to an aspect of the present invention, the substrate has an opening, and at least a part of the signal transmission circuit is provided on the opening through the dielectric. . Here, the “opening” is not limited to the one completely penetrating to the opposite side, and includes one that forms a recess. Thereby, for example, the dielectric constant of the silicon substrate can be lowered, and the dielectric loss of the signal flowing in the signal transmission circuit provided on the opening can be further reduced.

  According to one form of this invention, the said opening part has penetrated, It is characterized by the above-mentioned. Thereby, the dielectric loss of the signal flowing through the signal transmission circuit, for example, from the silicon substrate can be more reliably reduced.

  According to an aspect of the present invention, the signal transmission circuit is a high-frequency signal transmission circuit. Here, the “high-frequency signal” is a signal having a frequency of, for example, several hundred MHz to several hundred GHz band, and includes a so-called microwave and millimeter wave. This makes it possible to reduce signal attenuation due to, for example, a dielectric loss of a silicon substrate, which is a serious problem when signals are transmitted in, for example, CPW using micro and millimeter waves.

  According to an aspect of the present invention, a part of the signal transmission circuit includes a transmission path for a signal flowing through the signal transmission circuit. Thereby, the dielectric loss of the signal which flows through the transmission line (for example, CPW) can be reduced.

  According to one aspect of the present invention, a part of the signal transmission circuit includes an antenna electrically connected to the transmission path. Thereby, the dielectric loss of the signal flowing through the antenna can be reduced.

  According to an aspect of the present invention, a part of the signal transmission circuit includes a plurality of antennas as the antenna, and a switch that is electrically connected to the transmission path and can select at least one of the plurality of antennas. It is characterized by having. As a result, the antenna can be selected, and the transmission loss, the plurality of antennas, the switches, and the like can be all reduced to reduce the dielectric loss of the entire signal transmission circuit device.

  A method of manufacturing a signal transmission circuit device according to another aspect of the present invention includes a step of anodic bonding a substrate and a dielectric, a step of forming a signal transmission circuit on the opposite side of the dielectric from the substrate, Forming an opening in the substrate corresponding to a part of the signal transmission circuit.

  The present invention includes a step of anodic bonding the substrate and the dielectric by moving ions in the dielectric, and a step of forming the signal transmission circuit on the side opposite to the substrate side of the dielectric. A signal transmission circuit device in which the dielectric loss that the signal flowing through the dielectric receives from the dielectric or the substrate can be easily manufactured. Further, the dielectric constant of the substrate can be lowered, and the dielectric loss of the signal flowing in the signal transmission circuit provided on the opening can be further reduced.

  According to an embodiment of the present invention, the substrate is a silicon substrate, and the dielectric is Pyrex (registered trademark) glass. Thereby, silicon generally used in a signal transmission circuit device can be used, and Na ions in Pyrex (registered trademark) glass can be used for anodic bonding. Further, Pyrex (registered trademark) glass has almost the same thermal expansion coefficient as that of silicon and facilitates anodic bonding and the like, and a signal transmission circuit device can be manufactured at low cost.

  According to an aspect of the present invention, the signal transmission circuit is a high-frequency signal transmission circuit. As a result, for example, when signal transmission is performed in the CPW with micro and millimeter waves, a signal transmission circuit device in which signal attenuation due to dielectric loss, which has been a serious problem, is further reduced can be manufactured at low cost.

  According to an aspect of the present invention, the method further comprises a step of surface polishing the anodic bonded dielectric to a predetermined thickness, and the signal transmission circuit is formed on the surface polished dielectric. It is characterized by being. As a result, for example, Pyrex (registered trademark) glass can be formed to a thickness of 50 μm to 5 μm, the surface part that is anodically bonded can be used, and the dielectric loss of the signal flowing through the signal transmission circuit can be further reduced. In addition, the thickness of 50 μm to 5 μm makes the handling easy while achieving the effect of reducing the dielectric loss.

  According to an aspect of the present invention, a part of the signal transmission circuit includes at least one of a transmission path of a signal flowing through the signal transmission circuit, a switch electrically connected to the transmission path, and the switch. And a plurality of antennas to be selected. This makes it possible to select an antenna and manufacture a signal transmission circuit device in which the transmission path, the plurality of antennas, the switch, and the like all have low loss.

  In each of the above inventions, the order of the steps is not limited unless otherwise specified in the invention-specific matters or in the description of the effects.

  As described above, according to the present invention, the dielectric loss of the signal transmission circuit can be reduced and the electrical reliability thereof can be improved at low cost.

  In the following, a high-frequency signal transmission circuit device (hereinafter simply referred to as “circuit device”) and a method for manufacturing the same will be described as an example of the signal transmission circuit device with reference to the drawings.

  1 is a perspective view showing a part of a circuit device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA of FIG. 1, and FIG. 3 is a plan view of FIG.

  The circuit device 1 includes a silicon substrate (Si) 2, a Pyrex (registered trademark) glass 3 anodically bonded to the silicon substrate, and a signal transmission circuit formed on the opposite side of the Pyrex (registered trademark) glass 3 from the silicon substrate side. 4 is constituted by a CPW 5 as a transmission line that is a part of the transmission line 4.

  For example, as shown in FIG. 2, the silicon substrate 2 has an opening 6 penetrating from the joint surface 2a to the Pyrex (registered trademark) glass 3 to the opposite side surface 2b, and the lateral width B of the opening 6 (in FIG. 2). B) is formed to be larger than the lateral width C (C in FIG. 2) of CPW5.

  The silicon substrate 2 is formed with a thickness (Z-axis direction in FIG. 1) of, for example, 250 μm (± 10%).

  The Pyrex (registered trademark) glass 3 is anodically bonded to the silicon substrate 2 as shown in FIG. 1, for example, and the thickness (in the Z-axis direction in FIG. 1) is formed as a thin film having a thickness of 50 μm (± 10%), for example. ing.

  The circuit device 1 is, for example, a coplanar waveguide type circuit device. As shown in FIG. 3, the CPW 5 has a signal line 7 and ground lines 8 and 9 formed on both sides of the signal line 7. The signal line 7 and the ground lines 8 and 9 are formed on the Pyrex (registered trademark) glass surface 3 a so as to straddle the opening 6 of the silicon substrate 2 via the Pyrex (registered trademark) glass 3, and transmit signals. A part of the circuit 4 is provided on the opening 6 through the Pyrex (registered trademark) glass 3.

  Further, for example, as shown in FIG. 3, the ground lines 8 and 9 are formed to have a larger width than the signal line 7. The signal line 7 and the ground lines 8 and 9 have a structure in which gold (Au) is laminated on titanium (Ti).

  In the above description, the signal line 7 and the ground lines 8 and 9 have been described as having a substantially rectangular outer shape as shown in FIGS. 1 and 3, but the present invention is not limited thereto. The line width may be designed and formed to match.

  Next, a method for manufacturing the circuit device 1 will be described.

  4 is a flowchart of a method of manufacturing a circuit device, FIG. 5 is an explanatory diagram of bonding between a silicon substrate and Pyrex (registered trademark) glass, FIG. 6 is an explanatory diagram of a process of forming a CPW and an opening, and FIG. FIG. 7 is a plan view of each of FIGS. 6B and 6D.

  First, as shown in FIG. 5 (a), a silicon substrate 2 and Pyrex (registered trademark) glass 3 whose one surface is optically mirror-polished are overlapped with each other and placed on the hot plate 10 with the silicon substrate side as an installation surface. At the same time, the electrode 11 is pressed against the Pyrex (registered trademark) glass side.

  In this state, the temperature of the hot plate 10 is raised to 450 ° C., and a direct current of −700 V is applied to the electrode 11. Then, movement of Na ions in the Pyrex (registered trademark) glass occurs, and the Pyrex (registered trademark) glass 3 and the silicon substrate 2 are anodic bonded at the interface (ST101). Further, as shown in FIG. 5B, the Pyrex (registered trademark) glass 3 that has been anodically bonded is optically polished to 50 μm (± 10 percent), for example, and the silicon substrate 2 also becomes 250 μm (± 10 percent). Thus, optical polishing is performed (ST102). Of course, the thickness D (D in FIG. 5B) of ST102 of the Pyrex (registered trademark) glass 3 is not limited to 50 μm (± 10 percent), and may be, for example, 5 μm to 50 μm. As a result, the dielectric loss can be reduced and the handling can be facilitated.

  Next, as shown in FIG. 6A, a photoresist is spin-coated by photolithography on the Pyrex (registered trademark) glass surface 3a opposite to the bonding surface of the Pyrex (registered trademark) glass 3, mask exposure, Development is performed to form, for example, a CPW pattern (ST103).

  Further, for example, titanium (Ti) and gold (Au) are formed on the patterned resist mask 12a by sputtering at a film thickness of approximately 20 nm and 700 nm, respectively (ST104), and only CPW5 is removed from the acetone solution by lift-off in FIG. It is formed as shown in b) and FIG. 7A (ST105). Thereby, the signal line 7 and the ground lines 8 and 9 as the CPW 5 are provided on the silicon substrate 2 through the Pyrex (registered trademark) glass 3.

  Further, as shown in FIG. 6C, a photoresist is spin-coated on the opposite side surface 2b of the silicon substrate 2, and mask exposure and development are performed to form a resist mask 12b having the same pattern as the opening 6 (ST106).

  Thereafter, an opening 6 is formed in the silicon substrate 2 by using a Bosch process in which a polymerization film process is repeated with fluorine, oxygen mixed gas plasma and C4F8 gas in a DRIE (Deep Reactive Ion Etching) apparatus (ST107). That is, as shown in FIGS. 6D and 7B, the opening 6 is formed in a substantially rectangular parallelepiped so as to penetrate from the bonding surface 2a of the silicon substrate to the Pyrex (registered trademark) glass 3 to the opposite side surface 2b. Is done. In addition, in the opening 6, for example, as shown in FIG. 7B, the signal line 7 and the ground lines 8 and 9 straddle the opening 6 of the silicon substrate 2 through the Pyrex (registered trademark) glass 3. Formed as follows.

  Then, the resist mask 12b is removed with a stripping solution (ST108), and the circuit device 1 is completed by attaching other necessary components (ST109).

  In the above description, the opening 6 in the silicon substrate 2 is such that the signal line 7 and the ground lines 8 and 9 of the CPW 5 straddle the opening 6 of the silicon substrate 2 through the Pyrex (registered trademark) glass 3. However, the present invention is not limited to this. For example, a concave portion may be formed on the joint surface 2a with the Pyrex (registered trademark) glass 3 without penetrating to the opposite side surface 2b. Further, for example, even when no opening is formed as shown in FIG. 8, the dielectric loss can be suppressed as compared with the case of using conventional SiO 2 as described later. However, it is of course more preferable to form the opening 6 as a through hole. Here, FIG. 8 is a perspective view showing a part of the circuit device in which the opening is not formed.

  In the above description, the CPW 5 is formed on the Pyrex (registered trademark) glass surface 3a and then the opening 6 is formed in the silicon substrate 2. However, after the opening 6 is formed in the silicon substrate 2 after anodic bonding, the Pyrex is formed. It is considered possible to form CPW5 on the (registered trademark) glass surface 3a.

  As described above, according to the present embodiment, the thin film Pyrex (registered trademark) glass 3 that is anodically bonded to the silicon substrate and ion-transferred is provided between the CPW 5 and the silicon substrate 2 constituting the signal transmission circuit. . Therefore, the dielectric loss that the signal flowing through the CPW 5 receives from the Pyrex (registered trademark) glass 3 and the silicon substrate 2 can be reduced. Further, since the Pyrex (registered trademark) glass can be used at a lower cost than the quartz substrate, the cost of the circuit device 1 can be reduced.

  Further, a silicon substrate generally used in circuit devices can be used, and Na ions in Pyrex (registered trademark) glass can be used for anodic bonding. Further, the Pyrex (registered trademark) glass 3 has almost the same thermal expansion coefficient as that of the silicon substrate 2 and anodic bonding is easy, so that the circuit device 1 can be manufactured at low cost.

  Further, since the opening 6 penetrates from the bonding surface 2a of the silicon substrate 2 to the Pyrex (registered trademark) glass 3 to the opposite side surface 2b, a signal transmission circuit, for example, a signal flowing through the CPW 5 from the silicon substrate 2 is passed through. Dielectric loss can be reduced more reliably.

  In particular, when a signal is transmitted, for example, during CPW using micro waves or millimeter waves, signal attenuation due to dielectric loss of the silicon substrate 2, which has been a serious problem, can be further reduced.

  For example, as shown in FIG. 9, the measurement probe 14 a connected to the output side 13 a of the network analyzer 13 is brought into contact with one end of each of the signal line 7 and the ground lines 8 and 9 of the CPW 5. And the measurement probe 14b connected to the input side 13b was made to contact the other end, and the transmission characteristics were compared. Here, FIG. 9 is a conceptual diagram of a network analyzer that measures CPW.

  As a sample, (1) high-resistance silicon without the opening 6 and (2) quartz glass without the opening 6 were used, and CPW5 formed thereon was prepared. In addition, (3) a thin film SiO 2 of 3 μm was formed on a normal silicon substrate, and CPW 5 was formed thereon to provide an opening 6, and (4) (3) an opening 6 was not provided. . Further, (5) Pyrex (registered trademark) glass and a silicon substrate are anodically bonded as shown in FIG. 8 and the opening 6 is not formed. (6) Pyrex (registered trademark) glass and silicon as shown in FIG. What prepared the opening part 6 by anodically bonding with the board | substrate was prepared.

  The measurement results of the transmission characteristics by the network analyzer 13 of the above sample are as shown in the table of FIG. 10, and the following points were clarified. Here, FIG. 10 is a table showing the measurement results of the sample transmission characteristics by the network analyzer.

  First, as shown in FIG. 8 of (5), Pyrex (registered trademark) glass and a silicon substrate are not anodic bonded to form the opening 6, which is about 1/4 at 50 GHz compared to (4). The transmission loss was S21 (dB / cm). This suggests that the dielectric loss of the high-frequency signal transmission circuit can be reduced by using a Pyrex (registered trademark) glass 3 that is a thin film (for example, a film thickness of 50 μm ± 10%) between the CPW 5 and the silicon substrate 2. .

  Further, when the opening 6 is formed by anodically bonding the Pyrex (registered trademark) glass of (6) and a silicon substrate, the transmission loss is about 2.0 (dB / cm) at 50 GHz, which is equivalent to an expensive quartz glass. became. As a result, it is suggested that the opening 6 is modified only by the movement of Na as an effect of the surface of the Pyrex (registered trademark) glass 3, and even if inexpensive glass is used, the high-frequency signal transmission circuit is improved. It was suggested that the dielectric loss can be further reduced.

  In addition to the above, it has become possible to form antennas, MEMS switches, electrodes, coils, and the like in addition to CPW5.

  Next, a case where a Kovar substrate is used instead of the silicon substrate 2 used in the above embodiment as a modification will be briefly described. In the following description, the same components and functions of the circuit device 1 according to the above-described embodiment will not be described or will be mainly described.

  The Kovar substrate 15 is an alloy made of iron, nickel, cobalt or the like, and has an expansion coefficient similar to that of the Pyrex (registered trademark) glass 3, and is anodically bonded to the Pyrex (registered trademark) glass 3 in the same manner as the silicon substrate 2. The circuit device 1 can be used.

  However, when the Kovar substrate 15 is used instead of the silicon substrate 2, the anodic bonding with the Pyrex (registered trademark) glass 3 is performed by setting the temperature of the hot plate 10 to 400 ° C. and applying the applied voltage in the opposite direction to that of the silicon substrate. + 700V. Further, the mixed plasma for forming the opening 6 becomes fluorine, chlorine, oxygen mixed plasma in the Kovar substrate 15.

  As described above, according to this modification, the Kovar substrate 15 has a thermal expansion coefficient close to that of the Pyrex (registered trademark) glass 3, so that stable and easy anodic bonding is possible, and the circuit device 1 is manufactured at low cost. it can. Further, since the Kovar substrate 15 is an alloy and is bonded to, for example, Pyrex (registered trademark) glass 3 on which CPW 5 is formed, a shielding effect can be expected.

  11 is a plan view of a circuit device according to another embodiment of the present invention, FIG. 12 is a cross-sectional view taken along line EE of FIG. 11, and FIG. 13 is a cross-sectional view taken along line FF of FIG.

  The circuit device 101 includes, for example, a silicon substrate (Si) 102, a Pyrex (registered trademark) glass 3 anodically bonded to the silicon substrate, and a silicon substrate of the Pyrex (registered trademark) glass 3, as shown in FIGS. A signal transmission circuit 104 formed on the opposite side to the first side. The signal transmission circuit 104 includes a CPW 105 as a transmission path, patch antennas 121 and 122 as antennas, MEMS switches 123 and 124 as switches, and the like.

  Further, as shown in FIG. 11, the signal transmission circuit 104 has a CPW signal input unit 110 that receives a signal from a transmission circuit (not shown) or the like. The CPW signal input unit 110 includes ground lines 108 and 109 and a signal line 107 of the CPW 105 that are electrically connected to the silicon substrate 102.

  Further, the signal line 107 extends over the opening of the silicon substrate 102, is T-branched, and is electrically connected to patch antennas 121 and 122 arranged on the left and right, respectively. The T-branched signal line 107 is provided with MEMS switches 123 and 124 on the way to the left and right patch antennas 121 and 122. Each of the MEMS switches 123 and 124 can be electrically connected to a MEMS switch control power source (not shown).

  Further, the MEMS switches 123 and 124 include a dielectric thin film 125 that covers the surface of the signal line 107 provided on the Pyrex (registered trademark) glass surface 3a as shown in FIG. 12, for example, and a predetermined distance from the dielectric thin film 125. The solid ribbon electrode 126 intersecting with the signal line 107 is provided.

  Furthermore, the MEMS switches 123 and 124 are each 1/4 of the wavelength λ used in the arrangement direction of the patch antennas 121 and 122 (X-axis direction in FIG. 11) from the signal line 107 before T-branching as shown in FIG. The distance G (G in FIG. 11) is arranged.

  Therefore, when one of the three-dimensional ribbon electrodes 126 is electrically connected to the switch control power source, the MEMS switches 123 and 124 are affected by the electrostatic force between the connected three-dimensional ribbon electrode 126 and the dielectric thin film 125. The electrode 126 is in contact with the dielectric thin film 125. As a result, a short state at a high frequency due to the capacitance can be obtained, and the patch antennas 121 and 122 can be switched.

  Next, the silicon substrate 102 has an opening 106 penetrating from the bonding surface 102 a to the Pyrex (registered trademark) glass 3 to the opposite side surface 102 b. For example, as shown by a broken line in FIG. 11, the opening 106 has a patch antenna opening 106a so that each of the patch antennas 121 and 122 is disposed inside the opening through the Pyrex (registered trademark) glass 3. , 106b. Further, the MEMS switches 123 and 124 have MEMS switch openings 106c and 106d so that each of the MEMS switches 123 and 124 is disposed inside the opening via the Pyrex (registered trademark) glass 3. The patch antenna openings 106a and 106b and the MEMS switch openings 106c and 106d are connected to each other so that the signal line 107 is arranged inside the opening via the Pyrex (registered trademark) glass 3. A line opening 106e is provided.

  For example, as shown in FIG. 13, the patch antenna opening 106a is formed with a lateral width H (H in FIG. 13) larger than the lateral width of the patch antenna 121, and its inner wall is substantially in the direction of the surface of the Pyrex (registered trademark) glass. They are orthogonal to each other. The patch antenna opening 106b is formed in the same manner as the patch antenna opening 106a.

  Further, as shown in FIG. 12, the MEMS switch opening 106d is also formed to be longer than the length of the MEMS switch 124 in the longitudinal direction (Y-axis direction in FIG. 11), and its inner wall is substantially pyrex (registered). (Trademark) It is orthogonal to the glass surface direction. The MEMS switch opening 106c is formed in the same manner as the MEMS switch opening 106d.

  Further, since the silicon substrate 102 electrically connected to the ground lines 108 and 109 is divided into three blocks by the opening 106, for example, as shown in FIG. 11, a gold wire wire that electrically connects each of them. They are electrically connected by a bond 127.

  The silicon substrate 102 is formed with a thickness (in the Z-axis direction in FIG. 13) of, for example, 250 μm (± 10%), and the Kovar substrate 15 may be used instead of the silicon substrate 102 as described above. This is the same as the embodiment.

  As described above, according to the present embodiment, the patch antennas 121 and 122, the MEMS switches 123 and 124 of the circuit device 101, and the signal line 107 of the CPW 105 are all anodic-bonded through the thin Pyrex (registered trademark) glass 3. It is disposed within the range of the opening 106. Therefore, the patch antennas 121 and 122 can be easily selected, and the dielectric loss of the circuit device 101 can be reduced at low cost by the anodic-bonded Pyrex (registered trademark) glass 3 and the opening 106.

  The present invention has been described above with reference to preferred embodiments. However, the present invention is not limited to any of the above-described embodiments and modifications, and may be modified as appropriate within the scope of the technical idea of the present invention. The embodiment and the modification can be combined and implemented.

It is a perspective view which shows a part of circuit device which concerns on one embodiment of this invention. It is the sectional view on the AA line of FIG. It is a top view of FIG. It is a flowchart of the manufacturing method of the circuit device which concerns on one embodiment of this invention. It is explanatory drawing of joining of a silicon substrate and Pyrex (trademark) glass. It is explanatory drawing of the formation process of CPW and an opening part. It is a top view of each of Drawing 6 (b) and (d). It is a perspective view which shows a part of circuit device which does not form an opening part. It is a conceptual diagram of the network analyzer which measures CPW. It is the table | surface which showed the measurement result of the transmission characteristic of the sample by a network analyzer. It is a top view of the circuit device concerning other embodiments of the present invention. It is the EE sectional view taken on the line of FIG. It is FF sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,101 ... Circuit apparatus 2,102 ... Silicon substrate 3 ... Pyrex (registered trademark) glass 4,104 ... Signal transmission circuit 5,105 ... CPW
6, 106 ... opening 15 ... Kovar substrate 121, 122 ... patch antenna 123, 124 ... MEMS switch

Claims (15)

A substrate,
A signal transmission circuit provided on the substrate;
A signal transmission circuit device comprising: a dielectric provided between the substrate and the signal transmission circuit and anodically bonded to the substrate. The signal transmission circuit device according to claim 1,
The signal transmission circuit device, wherein the substrate is a silicon substrate, and the dielectric is Pyrex (registered trademark) glass. The signal transmission circuit device according to claim 1,
The signal transmission circuit device according to claim 1, wherein the substrate is made of metal, and the dielectric is Pyrex (registered trademark) glass. The signal transmission circuit device according to claim 3,
The signal transmission circuit device, wherein the metal is made of Kovar. The signal transmission circuit device according to claim 1,
The substrate has an opening;
At least a part of the signal transmission circuit is provided on the opening via the dielectric, and a signal transmission circuit device. The signal transmission circuit device according to claim 5,
The signal transmission circuit device, wherein the opening is penetrated. The signal transmission circuit device according to claim 6,
The signal transmission circuit device is a high-frequency signal transmission circuit. The signal transmission circuit device according to claim 7,
A part of the signal transmission circuit includes a transmission path for a signal flowing through the signal transmission circuit. The signal transmission circuit device according to claim 8,
A part of the signal transmission circuit includes an antenna electrically connected to the transmission line. The signal transmission circuit device according to claim 9,
A part of the signal transmission circuit includes a plurality of antennas as the antenna, and a switch electrically connected to the transmission path and capable of selecting at least one of the plurality of antennas. Circuit device. Anodic bonding of the substrate and the dielectric;
Forming a signal transmission circuit on the opposite side of the dielectric from the substrate side;
And a step of forming an opening in the substrate so as to correspond to at least a part of the signal transmission circuit. It is a manufacturing method of the signal transmission circuit device according to claim 11,
The method of manufacturing a signal transmission circuit device, wherein the substrate is a silicon substrate, and the dielectric is Pyrex (registered trademark) glass. It is a manufacturing method of the signal transmission circuit device according to claim 11,
The method for manufacturing a signal transmission circuit device, wherein the signal transmission circuit is a high-frequency signal transmission circuit. It is a manufacturing method of the signal transmission circuit device according to claim 11,
Further comprising a step of polishing the surface of the anodic bonded dielectric to a predetermined thickness,
The method of manufacturing a signal transmission circuit device, wherein the signal transmission circuit is formed on the surface-polished dielectric. It is a manufacturing method of the signal transmission circuit device according to claim 11,
A part of the signal transmission circuit includes a transmission path of a signal flowing through the signal transmission circuit, a switch electrically connected to the transmission path, and a plurality of antennas selected at least one by the switch. A method for manufacturing a signal transmission circuit device.

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