Composite sensor and method of manufacturing the same

Abstract

The composite sensor (1) includes: a first substrate (50); a second substrate (30) opposed to the first substrate (50) with a space therebetween; a first seal frame (43) that seals a first space (48) between the first substrate (50) and the second substrate (30); and a second seal frame (44) that seals a second space (49) between the first substrate (50) and the second substrate (30), either one of the first space (48) and the second space (49) is provided with an acceleration sensor (11), the other one is provided with an angular velocity sensor (12), a vacuum degree of the first space (48) is different from a vacuum degree of the second space (49), and the first seal frame (43) and the second seal frame (44) are each composed of a eutectic alloy.

Description

Technical Field

[0001] This invention relates to composite sensors and methods for manufacturing them. Background Technology

[0002] In composite sensors incorporating accelerometers and angular velocity sensors, the accelerometers and angular velocity sensors require different vacuum levels, and therefore are typically manufactured separately before mounting. However, mounting multiple sensors can sometimes lead to axial misalignment between them, hindering high performance. Therefore, a manufacturing method is being investigated that forms spaces with different vacuum levels within the same substrate and seals the accelerometer and angular velocity sensors.

[0003] For example, Patent Document 1 discloses a method for manufacturing a physical quantity sensor, characterized in that the manufacturing method comprises: a preparation step in which a support substrate and a sealing substrate are prepared, the support substrate having a first sensor element and a second sensor element, and the sealing substrate having a first recess and a second recess on the support substrate side and having a through hole communicating with the first recess; a joining step in which the sealing substrate is joined to the support substrate in such a way that the first sensor element is housed in the first recess and the second sensor element is housed in the second recess; and a sealing step in which a sealing material with a melting point lower than the melting point or softening point of the support substrate and the sealing substrate is filled into the through hole to seal the first recess.

[0004] For example, Patent Document 2 discloses a method for manufacturing a composite sensor. In this method, the movable body of an accelerometer and the vibrating body of an angular velocity sensor are separated by a wall and disposed on the same sensor wafer. A cover wafer with gaps corresponding to each sensor is formed. Through holes and bumps are formed in the sensor sealing part. In the first sealing process, the accelerometer is sealed at atmospheric pressure by anodic bonding. The internal pressure of the angular velocity sensor is adjusted through the ventilation path formed by the bumps and the through holes. In the second sealing process, a load is applied in a high-temperature atmosphere to deform the bumps. The sensor wafer is brought into contact with the cover wafer in a vacuum atmosphere to perform anodic bonding, thereby vacuum sealing the angular velocity sensor.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2016-33464

[0008] Patent Document 2: International Publication No. 2013 / 080238 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] However, the manufacturing method for the physical quantity sensor described in Patent Document 1 requires steps such as forming a through hole, preparing a sealing material, and melting the sealing material. This increases the number of manufacturing steps, sometimes leading to increased manufacturing costs, longer lead times, and higher defect rates. Furthermore, not only the joint between the support substrate and the sealing substrate, but also the through hole sealed by the sealing material can become a leakage path, thus sometimes increasing the rate of poor sealing and reducing reliability.

[0011] Furthermore, the manufacturing method of the composite sensor described in Patent Document 2 requires the provision of through-holes in the sensor wafer and bumps on the bonding surface of the cap wafer, which requires mirror finishing for anode bonding, thus complicating the manufacturing process. Additionally, the area around deformed bumps can become a leakage path, sometimes increasing the incidence of poor sealing and reducing reliability.

[0012] The present invention was made in view of the following circumstances, and the object of the present invention is to provide a composite sensor with a simple manufacturing process and high reliability, and a method for manufacturing the same.

[0013] Methods for solving problems

[0014] A composite sensor according to one embodiment of the present invention comprises: a first substrate; a second substrate disposed opposite to the first substrate at a distance; a first sealing frame sealing a first space between the first substrate and the second substrate; and a second sealing frame sealing a second space between the first substrate and the second substrate. An acceleration sensor is provided in either the first space or the second space, and an angular velocity sensor is provided in the other space. The vacuum degree of the first space is different from that of the second space. Both the first sealing frame and the second sealing frame are made of a eutectic alloy.

[0015] Another technical solution of the present invention provides a method for manufacturing a composite sensor, comprising: preparing a first substrate and a second substrate spaced apart from the first substrate; sealing a first space between the first substrate and the second substrate using a first sealing frame; and sealing a second space between the first substrate and the second substrate using a second sealing frame, wherein an acceleration sensor is provided in either the first space or the second space, and an angular velocity sensor is provided in the other space, the vacuum degree of the first space is different from that of the second space, and both the first sealing frame and the second sealing frame are made of a eutectic alloy.

[0016] Invention Effects

[0017] According to the present invention, a composite sensor with simple manufacturing process and high reliability, and a method for manufacturing the same, can be provided. Attached Figure Description

[0018] Figure 1This is a cross-sectional view of the composite sensor according to the first embodiment.

[0019] Figure 2 This is a top view of the composite sensor according to the first embodiment.

[0020] Figure 3 This is a flowchart illustrating a method for manufacturing the composite sensor according to the first embodiment.

[0021] Figure 4 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the first embodiment.

[0022] Figure 5 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the first embodiment.

[0023] Figure 6 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the first embodiment.

[0024] Figure 7 This is a cross-sectional view of the composite sensor according to the second embodiment.

[0025] Figure 8 This is a flowchart illustrating a method for manufacturing the composite sensor according to the second embodiment.

[0026] Figure 9 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the second embodiment.

[0027] Figure 10 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the second embodiment.

[0028] Figure 11 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the second embodiment.

[0029] Figure 12 This is a cross-sectional view of the composite sensor according to the third embodiment.

[0030] Figure 13 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the third embodiment.

[0031] Figure 14 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the third embodiment.

[0032] Figure 15 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the third embodiment.

[0033] Figure 16 This is a cross-sectional view of the composite sensor according to the fourth embodiment.

[0034] Figure 17This is a cross-sectional view showing the manufacturing process of the composite sensor according to the fourth embodiment.

[0035] Figure 18 This is a top view of the composite sensor according to the fifth embodiment.

[0036] Figure 19 This is a top view of the composite sensor according to the sixth embodiment. Detailed Implementation

[0037] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The drawings for this embodiment are illustrative, and the dimensions and shapes of the parts are schematic. They should not be interpreted as limiting the technical scope of the present invention to this embodiment.

[0038] <First Implementation>

[0039] First, refer to Figure 1 and Figure 2 The structure of the composite sensor 1 according to the first embodiment of the present invention will be described. Figure 1 This is a cross-sectional view of the composite sensor according to the first embodiment. Figure 2 This is a top view of the composite sensor according to the first embodiment.

[0040] The following describes the structure of the composite sensor 1. In the various figures, to clarify the relationships between the figures and aid in understanding the positional relationships of the components, an orthogonal coordinate system consisting of the X-axis, Y-axis, and Z-axis is sometimes used for convenience. Directions parallel to the X-axis, Y-axis, and Z-axis are designated as the X-axis direction, Y-axis direction, and Z-axis direction, respectively. The surface defined by the X-axis and Y-axis is designated as the XY plane. Furthermore, for convenience, the positive Z-axis direction (the direction of the arrow) is designated as "up" or "above," and the negative Z-axis direction (opposite to the direction of the arrow) is designated as "down" or "below," but the orientation of the composite sensor 1 is not limited to these definitions.

[0041] The composite sensor 1 includes a device layer 10, a lower cover 20, an upper cover 30, and a bonding layer 40. The lower cover 20, device layer 10, bonding layer 40, and upper cover 30 are stacked sequentially along the Z-axis direction. Hereinafter, the Z-axis direction in which the lower cover 20, device layer 10, bonding layer 40, and upper cover 30 are stacked is defined as the "thickness direction". The device layer 10 and the lower cover 20 are bonded together to form a MEMS substrate 50. The upper cover 30 is bonded to the device layer 10 of the MEMS substrate 50 via the bonding layer 40. In other words, the upper cover 30 is bonded to the lower cover 20 via the device layer 10 and the bonding layer 40. The lower cover 20 and the upper cover 30 are positioned opposite each other in the thickness direction, separated by the device layer 10 and the bonding layer 40. The lower cover 20, the bonding layer 40, and the upper cover 30 constitute an encapsulation structure, which forms an internal space that allows the movable portion of the device layer 10 to move. The MEMS substrate 50 is an example of a first substrate, and the upper cover 30 is an example of a second substrate.

[0042] When the device layer 10 and the lower cover 20 are regarded as MEMS substrate 50, for example, the silicon substrate P10 of the lower cover 20 (described later) is equivalent to the support substrate (substrate layer) of the SOI substrate, the silicon oxide film P11 of the lower cover 20 (described later) is equivalent to the BOX layer of the SOI substrate, and the silicon substrate F10 of the device layer 10 (described later) is equivalent to the active layer (device layer) of the SOI substrate.

[0043] Device layer 10 is formed of silicon substrate F10. Silicon substrate F10 is formed, for example, from single-crystal silicon. Silicon substrate F10 is formed, for example, from p-type silicon (Si) semiconductor. Silicon substrate F10 may contain boron (B) or the like as a p-type dopant. The resistivity of the silicon (Si) used in silicon substrate F10 is, for example, about 10 mΩ·cm. In addition, the material of device layer 10 is not limited to silicon semiconductor, and is not particularly limited as long as it can form an accelerometer and an angular velocity sensor.

[0044] Device layer 10 includes an accelerometer 11, an angular velocity sensor 12, and a bump 13. The accelerometer 11, angular velocity sensor 12, and bump 13 are formed by patterning the silicon substrate F10 using a subtractive processing method. The subtractive processing for forming the bump 13 is performed, for example, by isotropic wet etching using HF and HNO3. The subtractive processing for forming the accelerometer 11 and angular velocity sensor 12 is performed, for example, by dry etching called DRIE (Deep Reactive Ion Etching), which is a type of sputtering etching irradiated with ions accelerated by an electric field. Furthermore, the subtractive processing for forming the bump 13 and the subtractive processing for forming the accelerometer 11 and angular velocity sensor 12 are not limited to the above; other methods such as crystal anisotropic wet etching using an alkaline etchant, isotropic dry etching using reactive gases or plasma, vertical anisotropic dry etching using reactive ions, and laser etching can also be used.

[0045] Device layer 10 forms movable spaces 28 and 29 between itself and lower cover 20, and movable spaces 48 and 49 between itself and upper cover 30. Movable spaces 28 and 29 are separated, as are movable spaces 48 and 49. Movable spaces 28 and 48 are connected, and movable spaces 29 and 49 are connected. Movable spaces 28 and 48 are the movable spaces of accelerometer 11, and movable spaces 29 and 49 are the movable spaces of angular velocity sensor 12. Movable spaces 28 and 48 correspond to an example of the first space, and movable spaces 29 and 49 correspond to an example of the second space.

[0046] Accelerometer 11 detects acceleration in the X-axis, Y-axis, or Z-axis directions based on changes in the capacitance of the movable portion formed on the silicon substrate F10. To suppress free vibration of the movable portion, the accelerometer 11 is preferably subjected to a strong damping effect from the sealing gas. Therefore, the movable spaces 28 and 48 containing the accelerometer 11 are sealed with a low vacuum. The gas pressure in the movable spaces 28 and 48 is preferably between 0.1 atmospheres and 10 atmospheres, more preferably between 0.5 atmospheres and 5 atmospheres, for example, set to around 1 atmosphere. By setting the gas pressure in the movable spaces 28 and 48 to 0.1 atmospheres or more, preferably 0.5 atmospheres or more, the damping effect on the accelerometer 11 can be sufficiently obtained, improving the acceleration detection sensitivity. Furthermore, by setting the gas pressure to 10 atmospheres or less, preferably 5 atmospheres or less, excessive damping effect on the accelerometer 11 is suppressed, preventing a decrease in acceleration detection sensitivity.

[0047] The angular velocity sensor 12 detects the angular velocity about the X-axis, Y-axis, or Z-axis based on the change in capacitance of the movable part formed on the silicon substrate F10. To increase displacement and improve sensitivity, the angular velocity sensor 12 is preferably less susceptible to the damping effect of the sealing gas. Therefore, the movable spaces 29 and 49 containing the angular velocity sensor 12 are sealed with a high vacuum, higher than that of the movable spaces 28 and 48. The gas pressure of the movable spaces 29 and 49 is preferably about 1 Pa and less than 100 Pa, more preferably 5 Pa and less than 50 Pa, for example, set to about 10 Pa. By setting the gas pressure of the movable spaces 29 and 49 to 1 Pa or more, preferably 5 Pa or more, the increase in manufacturing cost and time can be suppressed. By setting the gas pressure of the movable spaces 29 and 49 to less than 100 Pa, preferably less than 50 Pa, the damping effect on the angular velocity sensor 12 can be sufficiently suppressed, and the detection sensitivity of the angular velocity is improved.

[0048] The movable spaces 28 and 48, which correspond to the first space, and the movable spaces 29 and 49, which correspond to the second space, are all filled with inactive gases. The inactive gases are nitrogen, argon, helium, neon, etc.

[0049] The protrusion 13 protrudes toward the upper cover 30. The protrusion 13 contacts the contact portion 46 described later, electrically connecting the MEMS substrate 50 and the upper cover 30.

[0050] The lower cover 20 is composed of a silicon substrate P10 and a silicon oxide film P11. The silicon oxide film P11 is disposed on the upper surface of the lower cover 20 that is bonded to the device layer 10. The silicon substrate P10 of the lower cover 20 is bonded to the silicon substrate F10 of the device layer 10 via the silicon oxide film P11.

[0051] The lower cover 20 has a base plate 22, a side wall 23, a support portion 24, and an inner wall 25. On the side of the lower cover 20 opposite the accelerometer 11 and angular velocity sensor 12 of the device layer 10, movable spaces 28 and 29 are formed, surrounded by the base plate 22 and the side wall 23. The inner wall 25 divides the movable spaces 28 and 29. The movable space 28 is a cuboid opening facing the accelerometer 11. The movable space 29 is a cuboid opening facing the angular velocity sensor 12.

[0052] The base plate 22 is disposed at a distance from the accelerometer 11 and the angular velocity sensor 12 in the thickness direction. The base plate 22 is a plate-shaped portion having a main surface extending along the XY plane. The base plate 22 is made of a silicon substrate P10.

[0053] Sidewall 23 extends from the periphery of base plate 22 toward top cover 30. Sidewall 23 is a frame-like portion that surrounds accelerometer 11 and angular velocity sensor 12 when viewed from above. The base end of sidewall 23 that connects to base plate 22 is formed of silicon substrate P10. A silicon oxide film P11 is provided at the top of sidewall 23, and sidewall 23 is bonded to silicon substrate F10 of device layer 10 via silicon oxide film P11.

[0054] The support portion 24 extends from the base plate 22 toward the device layer 10. The base end of the support portion 24, which is connected to the base plate 22, is provided with a silicon substrate P10. A silicon oxide film P11 is provided at the top end of the support portion 24, and the support portion 24 is connected to the silicon substrate F10 of the accelerometer 11 via the silicon oxide film P11.

[0055] The inner wall 25 extends from the center of the base plate 22 toward the top cover 30. Viewed from above, the inner wall 25 is located between the accelerometer 11 and the angular velocity sensor 12. The base end of the inner wall 25, which connects to the base plate 22, is formed of a silicon substrate P10. A silicon oxide film P11 is provided at the top of the inner wall 25, and the inner wall 25 is bonded to the silicon substrate F10 of the device layer 10 via the silicon oxide film P11.

[0056] The top cover 30 is flat. The top cover 30 is formed, for example, from a silicon substrate Q10 and a glass substrate Q11. The silicon substrate Q10 is formed, for example, from a p-type silicon (Si) semiconductor. The resistivity of the silicon (Si) used in the silicon substrate Q10 is, for example, about 10 mΩ·cm. The glass substrate Q11 is formed from silicate glass whose main component is silicon oxide (e.g., SiO2). Here, the main component in the glass refers to the component that accounts for 50% or more by mass of all components constituting the glass. As an example, the glass substrate Q11 is formed from alkali-free glass. When anodic bonding is performed between the glass substrate Q11 of the top cover 30 and the silicon substrate F10 of the device layer 10, the glass substrate Q11 needs to be alkaline glass. However, in this embodiment where bonding is performed using the eutectic alloy H10 described later, the glass substrate Q11 can also be formed from alkali-free glass. When the glass substrate Q11 is formed from alkali-free glass, no characteristic changes caused by the movement of alkali occur, thus improving the reliability of the composite sensor 1.

[0057] The glass substrate Q11 is mainly disposed on the side of the silicon substrate Q10 closest to the MEMS substrate 50. The silicon substrate Q10 is disposed in multiple regions that are separated from each other in the XY plane direction. The glass substrate Q11 extends between the multiple silicon substrates Q10 disposed in the regions that are separated from each other in the XY plane direction, electrically insulating the multiple silicon substrates Q10 from each other. The silicon substrate Q10 penetrates the glass substrate Q11 in the Z-axis direction in the region that overlaps with the contact portion 46 described later.

[0058] Furthermore, the material of the top cover 30 is not limited to the silicon substrate Q10 and the glass substrate Q11. The top cover 30 may have a silicon oxide film instead of the glass substrate Q11, or it may have a silicon oxide film in addition to the silicon substrate Q10 and the glass substrate Q11. Alternatively, the top cover 30 may be formed using a compound semiconductor substrate, a glass substrate, a ceramic substrate, a resin substrate, or a substrate composed of combinations thereof. Additionally, a through electrode penetrating the glass substrate Q11 may be provided in the area overlapping with the contact portion 46 described later. Such a through electrode may be formed, for example, by filling the through hole with polysilicon (Poly-Si), copper (Cu), or gold (Au).

[0059] The bonding layer 40 has sealing frames 43 and 44, a spacer 45, and a contact portion 46.

[0060] like Figure 1 As shown, sealing frames 43 and 44 join the MEMS substrate 50 and the top cover 30 together. Sealing frame 43 seals the movable space 48, and sealing frame 44 seals the movable space 49. Figure 2As shown, the sealing frame 43 is configured as a continuous frame in the circumferential direction surrounding the movable space 48, and the sealing frame 44 is configured as part of a frame in the circumferential direction surrounding the movable space 49. The sealing frame 44 is connected to the sealing frame 43, and the movable space 49 is surrounded by the sealing frames 43 and 44. The sealing frame 43 corresponds to an example of the first sealing frame, and the sealing frame 44 corresponds to an example of the second sealing frame.

[0061] like Figure 1 As shown, sealing frame 43 has a silicon oxide film G10 and a eutectic alloy H11 stacked in the thickness direction, and sealing frame 44 has a silicon oxide film G10 and a eutectic alloy H12 stacked in the thickness direction. Eutectic alloy H11 is disposed between silicon oxide film G10 and glass substrate Q11, and eutectic alloy H12 is disposed between silicon oxide film G10 and glass substrate Q11. Silicon oxide film G10 is disposed between silicon substrate F10 and eutectic alloy H11, and silicon oxide film G10 is disposed between silicon substrate F10 and eutectic alloy H12. Silicon oxide film G10 is disposed on the surface of silicon substrate F10 near the upper cover 30 side. Eutectic alloys H11 and H12 are disposed on the surface of glass substrate Q11 near the MEMS substrate 50 side. Silicon oxide film G10 prevents components of silicon substrate F10 from mixing into eutectic alloys H11 and H12.

[0062] Eutectic alloys H11 and H12 are, for example, Al-Ge-Ti eutectic alloys containing aluminum (Al), germanium (Ge), and titanium (Ti). The composition of eutectic alloy H11 differs from that of eutectic alloy H12. For instance, in eutectic alloy H11, the weight ratio of aluminum to germanium is Al:Ge = 1:1, while in eutectic alloy H12, the weight ratio is Al:Ge = 4:6.

[0063] Furthermore, eutectic alloys H11 and H12 are not limited to Al-Ge-Ti eutectic alloys; for example, they can also be Al-Ge eutectic alloys, Au-Sn eutectic alloys, or Al-Si eutectic alloys. Additionally, the weight ratio of aluminum to germanium in eutectic alloy H11 can be approximately the same as that in eutectic alloy H12.

[0064] The spacer 45 has an aluminum layer H31, a titanium layer H32, and an aluminum layer H33. The aluminum layer H31, titanium layer H32, and aluminum layer H33 are stacked sequentially in the Z-axis direction. The aluminum layer H31 is disposed on the side of the glass substrate Q11 of the upper cover 30 closest to the MEMS substrate 50. The titanium layer H32 is disposed on the side of the aluminum layer H31 closest to the MEMS substrate 50. The aluminum layers H31 and H33 are made of aluminum (Al), and the titanium layer H32 is made of titanium (Ti).

[0065] The spacer 45 controls the gap between the MEMS substrate 50 and the top cover 30. The spacer 45 extends from the top cover 30 in the negative Z-axis direction and abuts against the silicon substrate F10 of the device layer 10. At temperatures sufficiently lower than the melting point of aluminum, the spacer 45 maintains the gap between the MEMS substrate 50 and the top cover 30 under pressure in a direction that narrows the gap. At temperatures close to the melting point of aluminum, the spacer 45 deforms under pressure in a direction that narrows the gap between the MEMS substrate 50 and the top cover 30, and the gap narrows according to the pressure.

[0066] Contact portion 46 has an aluminum layer H31. Contact portion 46 extends from the upper cover 30 toward the negative Z-axis direction and abuts against the protrusion 13 of the silicon substrate F10 of the device layer 10. Contact portion 46 electrically connects the portion of the silicon substrate Q10 of the upper cover 30 exposed toward the MEMS substrate 50 to the protrusion 13 of the device layer 10. Thus, the external electrode (not shown) in the composite sensor 1 is electrically connected to the accelerometer 11 or the angular velocity sensor 12.

[0067] Next, refer to Figures 3 to 6 The manufacturing method of the composite sensor 1 according to the first embodiment will be explained. Figure 3 This is a flowchart illustrating a method for manufacturing the composite sensor according to the first embodiment. Figures 4 to 6 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the first embodiment.

[0068] In the process of manufacturing the composite sensor 1, firstly, a first substrate (MEMS substrate 50) and a second substrate (upper cover 30) are prepared (S10).

[0069] As part of the process for preparing the MEMS substrate 50, a silicon substrate P10 is first prepared and subjected to single-sided mirror polishing. A silicon oxide film P11 is formed on the mirror side of the silicon substrate P10. The silicon oxide film P11 and the upper surface side of the silicon substrate P10 are partially removed by dry etching or the like, thereby forming movable spaces 28 and 29.

[0070] Next, the silicon substrate F10 is bonded to the lower cover 20. First, the silicon substrate F10 is prepared and subjected to single-sided mirror polishing. The mirror surface of the silicon substrate F10 is brought into contact with the silicon oxide film P11 and heat-treated to directly bond the silicon substrate F10 and the silicon oxide film P11. Next, a protrusion 13 is formed on the silicon substrate F10 by wet etching. Alternatively, the protrusion 13 can also be formed before the silicon substrate F10 and the silicon oxide film P11 are directly bonded.

[0071] Next, the silicon substrate F10 is subjected to subtractive processing to form the device layer 10. Specifically, a photoresist is patterned on the upper surface of the silicon substrate F10, and the silicon substrate F10 is subjected to subtractive processing by dry etching. Thus, as... Figure 4 As shown, accelerometer 11 and angular velocity sensor 12 were fabricated.

[0072] Next, as Figure 4 As shown, metal frames 53 and 54 are provided. Metal frame 53 is an example of the first metal frame, and metal frame 54 is an example of the second metal frame. Metal frames 53 and 54 have a titanium layer H51 and a germanium layer H52. The steps of providing metal frames 53 and 54 include providing a silicon oxide film G10 in the area on the surface of the silicon substrate F10 where the sealing frames 43 and 44 are to be provided, providing a titanium layer H51 on the silicon oxide film G10, and providing a germanium layer H52 on the titanium layer H51. The titanium layer H51 of metal frames 53 and 54 is provided in the same process, and the germanium layer H52 of metal frames 53 and 54 is provided in the same process. The thickness of metal frame 53 along the Z-axis direction is equal to the thickness of metal frame 54 along the Z-axis direction.

[0073] As part of the process of preparing the top cover 30, firstly, a composite substrate composed of a silicon substrate Q10 and a glass substrate Q11 is prepared and then subjected to double-sided grinding.

[0074] Next, as Figure 4 As shown, metal frames 33 and 34, a spacer 45, and a contact portion 46 are provided. Metal frame 33 corresponds to an example of the third metal frame, and metal frame 34 corresponds to an example of the fourth metal frame. Metal frame 33 and spacer 45 have aluminum layer H31, titanium layer H32, and aluminum layer H33, metal frame 34 has titanium layer H32 and aluminum layer H33, and contact portion 46 has aluminum layer H31. The thickness of metal frame 33 along the Z-axis is equal to the thickness of spacer 45 along the Z-axis. The thickness of metal frame 34 along the Z-axis is smaller than the thickness of metal frame 33 along the Z-axis. The thickness of contact portion 46 along the Z-axis is smaller than the thickness of metal frame 34 along the Z-axis.

[0075] The steps of setting the metal frame 33 and the spacer 45 include setting an aluminum layer H31 on the glass substrate Q11 in the area where the sealing frame 43 and the spacer 45 are to be set, setting a titanium layer H32 on the aluminum layer H31, and setting an aluminum layer H33 on the titanium layer H32. The steps of setting the metal frame 34 include setting a titanium layer H32 on the glass substrate Q11 in the area where the sealing frame 44 is to be set, and setting an aluminum layer H33 on the titanium layer H32. The steps of setting the contact portion 46 include setting an aluminum layer H31 on the silicon substrate Q10 in the area where the contact portion 46 is to be set. The aluminum layer H31 of the metal frame 33, 34, and the contact portion 46 is set in the same process. The titanium layer H32 of the metal frames 33, 34, and the spacer 45 is set in the same process. The aluminum layer H33 of the metal frames 33, 34, and the spacer 45 is set in the same process.

[0076] like Figure 4 As shown, the MEMS substrate 50 and the top cover 30 are disposed opposite each other in the cavity CH. The gap between the metal frames 53 and 33 is smaller than the gap between the metal frames 54 and 34. The gap between the spacer 45 and the silicon substrate F10 is the same size as the gap between the contact portion 46 and the protrusion 13, larger than the gap between the metal frames 53 and 33, and smaller than the gap between the metal frames 54 and 34. That is, when the MEMS substrate 50 and the top cover 30 approach each other, first the metal frames 53 and 33 abut, then the spacer 45 abuts against the silicon substrate F10, simultaneously the contact portion 46 abuts against the protrusion 13, and finally the metal frames 54 and 34 abut.

[0077] Furthermore, as long as the metal frame 53 first abuts against the metal frame 33, the structure is not limited to one where the thickness of the metal frame 53 is equal to the thickness of the metal frame 54 and the thickness of the metal frame 33 is greater than the thickness of the metal frame 34. For example, it is also possible that the thickness of the metal frame 53 is greater than the thickness of the metal frame 54, and the thickness of the metal frame 33 is equal to the thickness of the metal frame 34. Alternatively, it is also possible that the thickness of the metal frame 53 is greater than the thickness of the metal frame 54, and the thickness of the metal frame 33 is greater than the thickness of the metal frame 34.

[0078] The air inside chamber CH is degassed, and chamber CH is filled with inactive gas GS. The vacuum level inside chamber CH is preferably 0.1 atm or higher and about 10 atm or lower, more preferably 0.5 atm or higher and about 5 atm or lower, for example, set to about 1 atm.

[0079] Furthermore, in this embodiment, the spacer portion 45 is provided on the upper cover 30, but the structure of the spacer portion is not limited to this. The spacer portion can be provided on the MEMS substrate, or on both the MEMS substrate and the upper cover. Similarly, the contact portion can be provided on the MEMS substrate, or on both the MEMS substrate and the upper cover.

[0080] Next, the first space (movable spaces 28, 48) is sealed (S20).

[0081] The steps of sealing the movable spaces 28 and 48 include inducing a eutectic reaction between the metal frame 53 and the metal frame 33. Specifically, the MEMS substrate 50 and the top cover 30 are heated to a first temperature and clamped together with a first pressure in a direction in which the MEMS substrate 50 and the top cover 30 approach each other. The first temperature is higher than the eutectic temperature of the Al-Ge-Ti eutectic alloy and lower than the melting point of aluminum. Furthermore, the first pressure is lower than the pressure required to deform aluminum at the first temperature. Therefore, when the MEMS substrate 50 and the top cover 30 approach each other, the metal frame 53 first comes into contact with the metal frame 33, inducing a eutectic reaction. By forming a eutectic alloy H11, the movable spaces 28 and 48 are sealed with a vacuum within the chamber CH.

[0082] As the eutectic reaction proceeds, metal frames 53 and 33 transform into molten eutectic alloy H11, and the MEMS substrate 50 and the top cover 30 approach each other further. At this time, the spacer 45 abuts against the MEMS substrate 50 and functions as a support to maintain the gap between the MEMS substrate 50 and the top cover 30. When the spacer 45 abuts against the MEMS substrate 50, a gap is formed between metal frames 54 and 34.

[0083] Next, increase the vacuum level in chamber CH (S30).

[0084] Specifically, with the spacer 45 abutting against the MEMS substrate 50, forming a gap between the metal frame 54 and the metal frame 34, the vacuum level inside the chamber CH is changed. By evacuating, the inactive gas GS inside the chamber CH is degassed, and the vacuum level increases. At this time, the vacuum level inside the chamber CH is preferably 1 Pa or more and about 100 Pa or less, more preferably 5 Pa or more and about 50 Pa or less, for example, set to about 10 Pa.

[0085] Next, the gap between the second metal frame (metal frame 54) and the fourth metal frame (metal frame 34) is closed (S40).

[0086] Specifically, while maintaining a constant first temperature, the pressure applied to the MEMS substrate 50 and the top cover 30 is changed from the first pressure to a second pressure. The second pressure is greater than the first pressure and is the pressure that deforms the aluminum at the first temperature. Therefore, the spacer 45 is crushed in the Z-axis direction, and the MEMS substrate 50 and the top cover 30 move closer together, with the metal frame 54 abutting against the metal frame 34. Furthermore, since the MEMS substrate 50 and the top cover 30 are heated to the first temperature, the eutectic alloy H11 melts. Therefore, by bringing the MEMS substrate 50 and the top cover 30 closer together, the thickness of the eutectic alloy H11 along the Z-axis decreases, extending along the XY plane.

[0087] Next, the second space (movable spaces 29, 49) is sealed (S50).

[0088] The steps of sealing the movable spaces 29 and 49 include a step of causing the metal frame 54 and the metal frame 34 to undergo a eutectic reaction. For example... Figure 6 As shown, a eutectic reaction occurs between metal frame 54 and metal frame 34 by bringing the metal frame 54, heated to a first temperature higher than the eutectic temperature of the Al-Ge-Ti eutectic alloy, into contact with it. By forming a eutectic alloy H12, the movable spaces 29 and 49 are sealed with a vacuum within the chamber CH.

[0089] Finally, composite sensor 1 was removed from chamber CH.

[0090] As described above, in one embodiment, the composite sensor 1 includes a MEMS substrate 50, a top cover 30 spaced apart from the MEMS substrate 50, a sealing frame 43 sealing movable spaces 28 and 48, and a sealing frame 44 sealing movable spaces 29 and 49. An accelerometer 11 is provided in the movable spaces 28 and 48, and an angular velocity sensor 12 is provided in the movable spaces 29 and 49. The vacuum degree of the movable spaces 28 and 48 is lower than that of the movable spaces 29 and 49. The sealing frames 43 and 44 are both made of eutectic alloy.

[0091] Therefore, by mounting the accelerometer 11 and the angular velocity sensor 12 on a single MEMS substrate 50, axial misalignment between the sensors can be suppressed, achieving high performance of the composite sensor 1. Furthermore, the two movable spaces are sealed by the MEMS substrate 50, the top cover 30, and the sealing frames 43 and 44, without through holes, bumps, or other features for adjusting the vacuum level of the two movable spaces. This simplifies the manufacturing process. Additionally, since there are fewer potential leakage paths, reliability is improved. Moreover, because the MEMS substrate 50 and the top cover 30 are joined using a eutectic alloy, the bonding surface of the substrates can also be made of alkali-free glass. Since alkali-free glass does not exhibit characteristic changes caused by alkali movement, reliability is improved compared to alkali glass.

[0092] Alternatively, angular velocity sensors 12 can be installed in movable spaces 28 and 48, and acceleration sensors 11 can be installed in movable spaces 29 and 49. In this case, the vacuum level of movable spaces 28 and 48 is higher than that of movable spaces 29 and 49.

[0093] As one of the above methods, it also includes a spacer portion 45 disposed between the MEMS substrate 50 and the top cover 30, the spacer portion 45 having a metal layer made of the metal of the eutectic alloy that makes up the sealing frames 43 and 44.

[0094] Therefore, the spacer 45 functions as a support to maintain the gap between the MEMS substrate 50 and the top cover 30, thereby preventing the gap between the MEMS substrate 50 and the top cover 30 from changing undesirably during the manufacturing process. Thus, the vacuum levels of the movable spaces 28 and 48 and the movable spaces 29 and 49 can be appropriately set, improving reliability. Furthermore, since the spacer 45 can be provided simultaneously with the process of setting the sealing frames 43 and 44, it can be provided without increasing the number of manufacturing processes.

[0095] Alternatively, the manufacturing method of the composite sensor 1 includes the steps of preparing a MEMS substrate 50 and a top cover 30, sealing movable spaces 28 and 48 using a sealing frame 43, and sealing movable spaces 29 and 49 using a sealing frame 44. An accelerometer 11 is provided in movable spaces 28 and 48, and an angular velocity sensor 12 is provided in movable spaces 29 and 49. The vacuum degree of movable spaces 28 and 48 is lower than that of movable spaces 29 and 49. Both sealing frames 43 and 44 are made of eutectic alloy.

[0096] Therefore, by mounting the accelerometer 11 and the angular velocity sensor 12 on a single MEMS substrate 50, axial misalignment between the sensors can be suppressed, achieving high performance in the composite sensor 1. Furthermore, by sealing the two movable spaces using the MEMS substrate 50, the top cover 30, and the sealing frames 43 and 44, the manufacturing method of the composite sensor 1 eliminates the need for steps such as providing through holes or bumps to adjust the vacuum level of the two movable spaces in the MEMS substrate 50, the top cover 30, and the sealing frames 43 and 44. This simplifies the manufacturing process. Additionally, since there are fewer potential leakage paths, reliability is improved. Moreover, since the MEMS substrate 50 and the top cover 30 are joined using a eutectic alloy, the bonding surface of the substrates can also be made of alkali-free glass. Because alkali-free glass does not exhibit characteristic changes caused by alkali movement, reliability is improved compared to alkali glass.

[0097] As one of the above methods, the steps of preparing the MEMS substrate 50 include setting metal frames 53 and 54 on the side opposite to the top cover 30, preparing the top cover 30 includes setting metal frames 33 and 34 on the side opposite to the MEMS substrate 50, sealing the movable spaces 28 and 48 with the sealing frame 43 includes performing a eutectic reaction between the metal frame 53 and the metal frame 33, and sealing the movable spaces 29 and 49 with the sealing frame 44 includes performing a eutectic reaction between the metal frame 54 and the metal frame 34. The steps of preparing the top cover 30 include setting a spacer 45 on the side opposite to the MEMS substrate 50. The manufacturing method of the composite sensor 1 further includes the following steps: after sealing the movable spaces 28 and 48 with the sealing frame 43 and before sealing the movable spaces 29 and 49 with the sealing frame 44, increasing the vacuum level of the chamber CH while the spacer 45 is in contact with the MEMS substrate 50 and a gap is formed between the metal frame 54 and the metal frame 34. Here, the spacer 45 has the same layer structure as the metal frame 33.

[0098] Therefore, the spacer 45 functions as a support to maintain the gap between the MEMS substrate 50 and the top cover 30, thereby preventing the gap between the MEMS substrate 50 and the top cover 30 from changing undesirably during the manufacturing process. Thus, the vacuum levels of the movable spaces 28 and 48 and the movable spaces 29 and 49 can be appropriately set, improving reliability. Furthermore, since the spacer 45 can be provided during the process of setting the metal frame 33, it can be provided without increasing the number of manufacturing processes.

[0099] Other embodiments will be described below. Furthermore, structures that are the same as or similar to those shown in the first embodiment will be labeled with the same or similar reference numerals, and their descriptions will be omitted where appropriate. Additionally, the same effects based on the same structure will not be mentioned individually.

[0100] <Second Implementation Method>

[0101] Next, refer to Figures 7 to 11 The structure and manufacturing method of the composite sensor 2 according to the second embodiment are explained. Figure 7 This is a cross-sectional view of the composite sensor according to the second embodiment. Figure 8 This is a flowchart illustrating a method for manufacturing the composite sensor according to the second embodiment. Figures 9 to 11 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the second embodiment.

[0102] like Figure 7 As shown, the composite sensor 2 differs from the composite sensor 1 in that it lacks the spacer portion 45. For example... Figure 8As shown, the manufacturing method of the composite sensor 2 includes a step S21 of temporarily sealing the first space instead of step S20 of sealing the first space, and a step S51 of sealing the first space and the second space instead of step S50 of sealing the second space.

[0103] like Figure 9 As shown, in step S10 of preparing the first substrate (MEMS substrate 50) and the second substrate (upper cover 30), the spacer portion 45 is not provided on the upper cover 30.

[0104] like Figure 10 As shown, in step S21, which temporarily seals the first space (movable spaces 28, 48), the MEMS substrate 50 and the top cover 30 are heated to a second temperature and clamped together with a second pressure in a direction in which the MEMS substrate 50 and the top cover 30 approach each other. The second temperature is a temperature higher than the eutectic temperature of the Al-Ge-Ti eutectic alloy and lower than the melting point of aluminum. The second pressure is the pressure at the second temperature that causes the metal frame 53 and the metal frame 33 to be in hermetically sealed contact. Under the action of the second pressure, one of the metal frames 53 and 33 is embedded in the other, and the metal frames 53 and 33 function as metal gaskets. The state in which the metal frames 53 and 33 are sealed together without undergoing a eutectic reaction is called "temporary sealing." At this time, the metal frames 33 and 53 also function as spacers forming a gap between the metal frames 54 and 34, and in this state, step S30, which increases the vacuum level within the chamber CH, is performed.

[0105] like Figure 11 As shown, in step S51, which seals the first space (movable spaces 28, 48) and the second space (movable spaces 29, 49), the MEMS substrate 50 and the top cover 30 are heated to a first temperature. The metal frames 53 and 34, which have already come into contact, undergo a eutectic reaction and become molten as a eutectic alloy H11, thus losing their function as spacers. The MEMS substrate 50 and the top cover 30 are brought closer together, and the metal frames 54 and 34 come into contact and undergo a eutectic reaction to form a eutectic alloy H12.

[0106] <Third Implementation Method>

[0107] Next, refer to Figures 12 to 15 The structure and manufacturing method of the composite sensor 3 according to the third embodiment are explained. Figure 12 This is a cross-sectional view of the composite sensor according to the third embodiment. Figures 13 to 15 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the third embodiment.

[0108] like Figure 12As shown, the composite sensor 3 has a height difference on the side of the upper cover 30 opposite to the MEMS substrate 50, and the thickness of the sealing frame 43 is smaller than the thickness of the sealing frame 44.

[0109] like Figure 13 As shown, the step of setting the top cover 30 includes setting a height difference between the area where the metal frame 33 is set and the area where the metal frame 34 is set. Specifically, the area of ​​the glass substrate Q11 where the metal frame 34 is to be set is subtractively processed into a concave shape. Thus, as Figure 14 As shown, even if the height of metal frame 33 is the same as the height of metal frame 34, a gap is formed between metal frame 54 and metal frame 34 when metal frame 53 abuts against metal frame 34. This is similar to the manufacturing method of the composite sensor 2 in the second embodiment, as... Figure 15 As shown, in step S51, sealing the first space (movable spaces 28, 48) and the second space (movable spaces 29, 49) is performed, forming a sealing frame 43 and a sealing frame 44 that is thicker than the sealing frame 43.

[0110] In addition, in this embodiment, a height difference is provided on the side of the upper cover 30, but a height difference can be provided on the side of the MEMS substrate 50, or a height difference can be provided on both sides of the MEMS substrate 50 and the upper cover 30.

[0111] <Fourth Implementation>

[0112] Next, refer to Figure 16 and Figure 17 The structure and manufacturing method of the composite sensor 4 according to the fourth embodiment are explained. Figure 16 This is a cross-sectional view of the composite sensor according to the fourth embodiment. Figure 17 This is a cross-sectional view showing the manufacturing process of the composite sensor according to the fourth embodiment.

[0113] like Figure 16 As shown, in the composite sensor 4, an angular velocity sensor 12 is sealed in movable spaces 28 and 48, and an acceleration sensor 11 is sealed in movable spaces 29 and 49. The vacuum level of movable spaces 28 and 48 is higher than that of movable spaces 29 and 49.

[0114] like Figure 17 As shown, the chamber CH is made into a high vacuum, and the movable spaces 28 and 48 are temporarily sealed. Then, with the gap between the metal frame 54 and the metal frame 34 formed, the vacuum level of the chamber CH is reduced. Next, the movable spaces 28 and 48 and the movable spaces 29 and 49 are sealed.

[0115] Furthermore, in this embodiment, the sensor sealed in the first and second spaces is the opposite of that in the second embodiment. The change point of reducing the vacuum level after temporary sealing is applied to the second embodiment, but the above-mentioned change point can also be applied to the first or third embodiment.

[0116] <Fifth Implementation>

[0117] Next, refer to Figure 18 The structure of the composite sensor 5 in the fifth embodiment will be explained. Figure 18 This is a top view of the composite sensor according to the fifth embodiment.

[0118] like Figure 18 As shown, when viewed from above, sealing frames 43 and 44 are arranged at intervals.

[0119] <Sixth Implementation>

[0120] Next, refer to Figure 19 The structure of the composite sensor 6 in the sixth embodiment will be explained. Figure 19 This is a top view of the composite sensor according to the sixth embodiment.

[0121] like Figure 19 As shown, when viewed from above, the sealing frame 43 is surrounded by the sealing frame 44. The first space is the inner side of the sealing frame 43, and the second space is the outer side of the sealing frame 43 and the inner side of the sealing frame 44.

[0122] The following are some or all of the embodiments of the present invention. Furthermore, the present invention is not limited to the following descriptions.

[0123] <1> A composite sensor, wherein,

[0124] This composite sensor has the following features:

[0125] 1st substrate;

[0126] The second substrate is positioned opposite the first substrate at a distance;

[0127] A first sealing frame, which seals the first space between the first substrate and the second substrate; and

[0128] The second sealing frame seals the second space between the first substrate and the second substrate.

[0129] An acceleration sensor is installed in either the first space or the second space, and an angular velocity sensor is installed in the other space.

[0130] The vacuum level of the first space is different from that of the second space.

[0131] Both the first and second sealing frames are made of eutectic alloy.

[0132] <2> according to <1> The composite sensor, wherein,

[0133] The composition of the eutectic alloy of the first sealing frame is different from that of the eutectic alloy of the second sealing frame.

[0134] <3> according to <2> The composite sensor, wherein,

[0135] The eutectic alloy of the first sealing frame and the eutectic alloy of the second sealing frame contain aluminum.

[0136] The aluminum content in the eutectic alloy of the first sealing frame is lower than that in the eutectic alloy of the second sealing frame.

[0137] <4> according to <1> to <3> The composite sensor described in any one of the following statements, wherein,

[0138] The thickness of the first sealing frame is different from that of the second sealing frame.

[0139] <5> according to <1> to <4> The composite sensor described in any one of the following statements, wherein,

[0140] The eutectic alloy that makes up the first sealing frame contains aluminum and germanium.

[0141] The eutectic alloy that makes up the second sealing frame contains aluminum and germanium.

[0142] <6> according to <5> The composite sensor, wherein,

[0143] The eutectic alloy metal that makes up the first sealing frame also includes titanium.

[0144] <7> according to <1> to <6> The composite sensor described in any one of the following statements, wherein,

[0145] The composite sensor also includes a spacer portion disposed between the first substrate and the second substrate.

[0146] The spacer has a metal layer made of the metal of the eutectic alloy that makes up the first sealing frame and the second sealing frame.

[0147] <8> according to <1> to <7> The composite sensor described in any one of the following statements, wherein,

[0148] When viewed from above, the first sealing frame is surrounded by the second sealing frame.

[0149] <9> according to <1> to <7> The composite sensor described in any one of the following statements, wherein,

[0150] When viewed from above, the first sealing frame and the second sealing frame are arranged at intervals.

[0151] <10> According to <1> to <7> The composite sensor described in any one of the following statements, wherein,

[0152] When viewed from above, the first sealing frame is connected to the second sealing frame.

[0153] <11> A method for manufacturing a composite sensor, wherein,

[0154] The manufacturing method includes:

[0155] The steps of preparing a first substrate and a second substrate that is spaced apart from the first substrate;

[0156] The step of sealing the first space between the first substrate and the second substrate using the first sealing frame; and

[0157] The step of sealing the second space between the first substrate and the second substrate using the second sealing frame.

[0158] An acceleration sensor is installed in either the first space or the second space, and an angular velocity sensor is installed in the other space.

[0159] The vacuum level of the first space is different from that of the second space.

[0160] Both the first and second sealing frames are made of eutectic alloy.

[0161] <12> According to <11> The method for manufacturing the composite sensor, wherein,

[0162] The steps of preparing the first substrate include setting a first metal frame and a second metal frame on the side opposite to the second substrate.

[0163] The steps for preparing the second substrate include setting a third metal frame and a fourth metal frame on the side opposite to the first substrate.

[0164] The step of sealing the first space using the first sealing frame includes a step of subjecting the first metal frame and the third metal frame to a eutectic reaction.

[0165] The step of sealing the second space using the second sealing frame includes the step of subjecting the second metal frame to a eutectic reaction with the fourth metal frame.

[0166] <13> According to <12> The method for manufacturing the composite sensor, wherein,

[0167] The step of preparing the second substrate also includes the step of providing a spacer portion on the side opposite to the first substrate.

[0168] The manufacturing method further includes the following steps: after sealing the first space with the first sealing frame and before sealing the second space with the second sealing frame, changing the vacuum level of the chamber containing the first and second substrates inside, while the spacer abuts against the first substrate and a gap is formed between the second and fourth metal frames.

[0169] <14> According to <13> The method for manufacturing the composite sensor, wherein,

[0170] The spacer has the same layered structure as the third metal frame.

[0171] <15> According to <12> to <14> The method for manufacturing the composite sensor described in any one of the following statements, wherein,

[0172] The manufacturing method further includes the following steps: bringing the first metal frame and the third metal frame into contact at a temperature lower than the eutectic temperature of the eutectic alloy, and temporarily sealing the first space.

[0173] The manufacturing method further includes the following steps: after temporarily sealing the first space and before sealing the second space using the second sealing frame, while the third metal frame abuts against the first metal frame and a gap is formed between the second metal frame and the fourth metal frame, the vacuum level of the chamber containing the first substrate and the second substrate is changed.

[0174] <16> According to <15> The method for manufacturing the composite sensor, wherein,

[0175] The thickness of the third metal frame is greater than the thickness of the fourth metal frame.

[0176] <17> According to <15> The method for manufacturing the composite sensor, wherein,

[0177] The step of setting the second substrate includes setting a height difference between the area where the third metal frame is set and the area where the fourth metal frame is set.

[0178] <18> According to <12> to <17> The method for manufacturing the composite sensor described in any one of the following statements, wherein,

[0179] The steps for setting the first and second metal frames include setting a germanium layer.

[0180] The steps for setting the third and fourth metal frames include setting the aluminum layer.

[0181] <19> According to <18> The method for manufacturing the composite sensor, wherein,

[0182] The steps for setting the third metal frame also include setting the titanium layer and setting the second aluminum layer.

[0183] The steps for setting the fourth metal frame also include setting a titanium layer.

[0184] As described above, according to one aspect of the present invention, a composite sensor with simple manufacturing process and high reliability, and a method for manufacturing the same, can be provided.

[0185] Furthermore, the embodiments described above are intended to facilitate understanding of the present invention and are not intended to limit the scope of the invention. The present invention can be modified / improved without departing from its spirit, and the present invention also includes its equivalents. That is, embodiments obtained by those skilled in the art through appropriate design modifications to each embodiment are also included within the scope of the present invention as long as they possess the features of the present invention. For example, the elements, their configurations, materials, conditions, shapes, dimensions, etc., of each embodiment are not limited to the illustrated elements, their configurations, materials, conditions, shapes, dimensions, etc., and can be appropriately modified. In addition, the elements of each embodiment can be combined within a technically feasible range, and any combination thereof that includes the features of the present invention is also included within the scope of the present invention.

[0186] Explanation of reference numerals in the attached figures

[0187] 1. Composite sensor; 10. Device layer; 11. Accelerometer; 12. Angular velocity sensor; 20. Lower cover; 28, 29. Movable space; 30. Upper cover; 33, 34. Metal frame; 40. Bonding layer; 48, 49. Movable space; 43, 44. Sealing frame; 45. Spacer; 46. Contact part; 50. MEMS substrate; 53, 54. Metal frame; P10, Q10, F10, Silicon substrate; P11, G10, Silicon oxide film; Q11, Glass substrate; H11, H12, Eutectic alloy; H31, H33, Aluminum layer; H32, H51, Titanium layer; H52, Germanium layer; GS, Inactive gas.

Claims

1. A composite sensor, wherein, This composite sensor has the following features: 1st substrate; The second substrate is positioned opposite the first substrate at a distance; A first sealing frame, which seals the first space between the first substrate and the second substrate; and The second sealing frame seals the second space between the first substrate and the second substrate. An acceleration sensor is provided in either the first space or the second space, and an angular velocity sensor is provided in the other. The vacuum level of the first space is different from that of the second space. Both the first sealing frame and the second sealing frame are made of eutectic alloy.

2. The composite sensor according to claim 1, wherein, The composition of the eutectic alloy of the first sealing frame is different from that of the eutectic alloy of the second sealing frame.

3. The composite sensor according to claim 2, wherein, The eutectic alloy of the first sealing frame and the eutectic alloy of the second sealing frame contain aluminum. The aluminum content in the eutectic alloy of the first sealing frame is smaller than the aluminum content in the eutectic alloy of the second sealing frame.

4. The composite sensor according to any one of claims 1 to 3, wherein, The thickness of the first sealing frame is different from the thickness of the second sealing frame.

5. The composite sensor according to any one of claims 1 to 4, wherein, The eutectic alloy comprising the first sealing frame contains aluminum and germanium. The metals comprising the eutectic alloy of the second sealing frame include aluminum and germanium.

6. The composite sensor according to claim 5, wherein, The metals comprising the eutectic alloy of the first sealing frame also include titanium.

7. The composite sensor according to any one of claims 1 to 6, wherein, The composite sensor also includes a spacer portion disposed between the first substrate and the second substrate. The spacer portion has a metal layer made of the metal of the eutectic alloy that makes up the first sealing frame and the second sealing frame.

8. The composite sensor according to any one of claims 1 to 7, wherein, When viewed from above, the first sealing frame is surrounded by the second sealing frame.

9. The composite sensor according to any one of claims 1 to 7, wherein, When viewed from above, the first sealing frame and the second sealing frame are arranged at intervals.

10. The composite sensor according to any one of claims 1 to 7, wherein, When viewed from above, the first sealing frame is connected to the second sealing frame.

11. A method for manufacturing a composite sensor, wherein, The manufacturing method includes: The steps of preparing a first substrate and a second substrate that is spaced apart from the first substrate; The step of sealing the first space between the first substrate and the second substrate using the first sealing frame; and The step of sealing the second space between the first substrate and the second substrate using the second sealing frame. An acceleration sensor is provided in either the first space or the second space, and an angular velocity sensor is provided in the other. The vacuum level of the first space is different from that of the second space. Both the first sealing frame and the second sealing frame are made of eutectic alloy.

12. The method for manufacturing the composite sensor according to claim 11, wherein, The step of preparing the first substrate includes setting a first metal frame and a second metal frame on the side opposite to the second substrate. The step of preparing the second substrate includes setting a third metal frame and a fourth metal frame on the side opposite to the first substrate. The step of sealing the first space using the first sealing frame includes a step of subjecting the first metal frame to a eutectic reaction with the third metal frame. The step of sealing the second space using the second sealing frame includes the step of subjecting the second metal frame to a eutectic reaction with the fourth metal frame.

13. The method for manufacturing the composite sensor according to claim 12, wherein, The step of preparing the second substrate further includes the step of providing a spacer portion on the side opposite to the first substrate. The manufacturing method further includes the following step: after sealing the first space using the first sealing frame and before sealing the second space using the second sealing frame, while the spacer abuts against the first substrate and a gap is formed between the second metal frame and the fourth metal frame, the vacuum level of the chamber containing the first substrate and the second substrate is changed.

14. The method for manufacturing the composite sensor according to claim 13, wherein, The spacer portion has the same layer structure as the third metal frame.

15. The method for manufacturing the composite sensor according to any one of claims 12 to 14, wherein, The manufacturing method further includes the following steps: bringing the first metal frame into contact with the third metal frame at a temperature lower than the eutectic temperature of the eutectic alloy to temporarily seal the first space. The manufacturing method further includes the following steps: after temporarily sealing the first space and before sealing the second space using the second sealing frame, while the third metal frame abuts against the first metal frame and a gap is formed between the second metal frame and the fourth metal frame, changing the vacuum level of the chamber containing the first substrate and the second substrate inside.

16. The method for manufacturing the composite sensor according to claim 15, wherein, The thickness of the third metal frame is greater than the thickness of the fourth metal frame.

17. The method for manufacturing the composite sensor according to claim 15, wherein, The step of setting the second substrate includes setting a height difference between the area where the third metal frame is set and the area where the fourth metal frame is set.

18. The method for manufacturing the composite sensor according to any one of claims 12 to 17, wherein, The steps of setting the first metal frame and the second metal frame include setting a germanium layer. The steps of setting the third metal frame and the fourth metal frame include setting an aluminum layer.

19. The method for manufacturing the composite sensor according to claim 18, wherein, The steps of setting the third metal frame also include setting a titanium layer and setting a second aluminum layer. The steps for setting the fourth metal frame also include setting a titanium layer.

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