Manufacturing method of physical amount sensor
The manufacturing method improves bonding strength and stability in physical quantity sensors by using a protective film and recess formation, along with protrusions and conductive films, addressing issues of adhesion and malfunction.
Patent Information
- Application Number
- JP2024060022
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-04-03
- Publication Date
- 2025-10-16
AI Technical Summary
The bonding strength between the substrate and the lid in conventional physical quantity sensors is inadequate, leading to potential issues such as poor adhesion and malfunction of the movable body.
A manufacturing method involving the preparation of a substrate with a protective film and a recess, followed by etching to form a movable body, and bonding the substrate and lid using a bonding material to enhance adhesion, while incorporating features like protrusions and conductive films to prevent sticking and improve accuracy.
The method enhances the bonding strength and prevents movable body sticking, ensuring stable operation and improved accuracy of the physical quantity sensor.
Smart Images
Figure 2025157785000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a method for manufacturing a physical quantity sensor. [Background technology]
[0002] In recent years, physical quantity sensors using MEMS (Micro Electro Mechanical System) technology have been developed. As one such physical quantity sensor, Patent Document 1 describes a physical quantity sensor having a triaxial acceleration sensor element and a triaxial angular velocity sensor element. In the physical quantity sensor described in Patent Document 1, a substrate and a lid are joined with a bonding material, and each sensor element is housed in the housing space between the substrate and the lid. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2018-169365 Summary of the Invention [Problem to be solved by the invention]
[0004] The present invention provides a method for manufacturing a physical quantity sensor that improves the bonding strength between the substrate and the lid in such a conventional physical quantity sensor. [Means for solving the problem]
[0005] A manufacturing method of a physical quantity sensor according to one aspect of the present application is a manufacturing method of a physical quantity sensor having a substrate having a movable body, a lid body, and a bonding material that bonds the substrate and the lid body, the manufacturing method including the steps of: preparing the substrate; preparing the lid body; and bonding the substrate and the lid body together via the bonding material to seal the movable body between the substrate and the lid body. The preparing the substrate step includes the steps of: preparing a first substrate having a protective film in a region where the lid body is to be bonded; preparing a second substrate having a recess facing the protective film; bonding the first substrate and the second substrate together so that the protective film is disposed in the recess; etching the second substrate to form the movable body; and removing the protective film. [Brief explanation of the drawings]
[0006] [Figure 1] FIG. 1 is a perspective view showing a schematic configuration of a physical quantity sensor device according to a first embodiment. [Figure 2] Cross-sectional view of the physical quantity sensor device taken along line AA in Figure 1. [Figure 3] FIG. 1 is a plan view of a physical quantity sensor. [Figure 4A] Cross-sectional view of the physical quantity sensor taken along line BB in Figure 3. [Figure 4B] Cross-sectional view of the physical quantity sensor taken along line CC in Figure 3. [Figure 5] 1 is a flowchart illustrating a manufacturing process of a physical quantity sensor. [Figure 6] 6 is a flowchart showing details of a substrate preparation step S1 in FIG. 5. [Figure 7] 7 is a flowchart showing details of a first substrate preparation step S11 in FIG. 6. [Figure 8] 7 is a flowchart showing details of the second substrate preparation step S12 in FIG. 6. [Figure 9] 9 is a flowchart showing details of a conductive film forming step S122 in FIG. 8. [Figure 10] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 11A] FIG. [Figure 11B] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 12A] FIG. [Figure 12B] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 13] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 14] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 15] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 16] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 17A] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 17B] FIG. [Figure 18] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 19] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 20] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 21] 1A to 1C are cross-sectional views showing one embodiment of a manufacturing process. [Figure 22A] FIG. 10 is a plan view showing one aspect of a manufacturing process according to a comparative example. [Figure 22B] 22B is a cross-sectional view of the silicon wafer substrate 20s taken along line EE in FIG. 22A. [Figure 22C] 10A and 10B are cross-sectional views showing an embodiment of a manufacturing process according to a comparative example. [Figure 23] FIG. 10 is an exploded perspective view showing a schematic configuration of an inertial measurement unit according to a second embodiment. [Figure 24] FIG. 1 is a perspective view of a substrate on which a physical quantity sensor is mounted. DETAILED DESCRIPTION OF THE INVENTION
[0007] In the embodiments of the present invention, components shown in the drawings may be shown with different scales for clarity. Drawings may show three mutually perpendicular axes: the X-axis, the Y-axis, and the Z-axis. In the following explanation, the tip of the arrows on the three axes may be referred to as the "plus side," and the base of the arrows may be referred to as the "minus side." The direction parallel to the X-axis may be referred to as the "X-axis direction," the direction parallel to the Y-axis may be referred to as the "Y-axis direction," and the direction parallel to the Z-axis may be referred to as the "Z-axis direction." Viewing in the Z-axis direction may be referred to as "planar view."
[0008] In the following description, for example, the expression "on the substrate" in relation to a substrate means that the substrate is placed in contact with the substrate, that the substrate is placed via another structure, or that a portion of the substrate is placed in contact with the substrate and a portion of the substrate is placed via another structure. The term "top surface" of a certain structure refers to the surface on the positive side of the Z axis direction of the structure, for example, "top surface of a movable body" refers to the surface on the positive side of the Z axis direction of the movable body. The term "bottom surface" of a certain structure refers to the surface on the negative side of the Z axis direction of the structure, for example, "the bottom surface of the movable body" refers to the surface on the negative side of the Z axis direction of the movable body. The term "surface" of a certain structure refers to the surface that appears on the outside of the structure.
[0009] 1. Embodiment 1 1.1. Physical Quantity Sensor Device and Physical Quantity Sensor Configuration 1 and 4B show schematic configurations of a physical quantity sensor device 1 and a physical quantity sensor 100 according to this embodiment.
[0010] FIG. 1 is a perspective view showing a schematic configuration of a physical quantity sensor device 1 according to a first embodiment. FIG. 2 is a cross-sectional view taken along line AA in FIG. 1. FIG. 3 is a plan view of a physical quantity sensor 100 housed in the physical quantity sensor device 1, with the lid 30 omitted for ease of explanation. FIG. 4A is a cross-sectional view of the physical quantity sensor 100 taken along line BB in FIG. 3. FIG. 4B is a cross-sectional view of the physical quantity sensor 100 taken along line CC in FIG. 3.
[0011] As shown in FIGS. 1 and 2, the physical quantity sensor device 1 has a package 40 and a structure 120 housed in the package 40. The package 40 is a container that houses the structure 120. The package 40 is composed of a box-shaped base portion 42 and a lid body 41, and houses the structure 120 in a housing space s1 sealed by a sealing member 44.
[0012] The package 40 has terminals 53 , electrode pads 54 , and castellations 43 . The terminal 53 is provided inside the base portion 42 and is connected to an IC (Integrated Circuit) 110 via a bonding wire 52 . The electrode pads 54 are provided on the lower surface 42b of the base portion 42. The electrode pads 54 are electrically connected to the corresponding terminals 53 via through-wirings (not shown) that penetrate the base portion 42. The castellations 43 are provided on the side surfaces of the base portion 42 in correspondence with the electrode pads 54 .
[0013] The structure 120 includes the physical quantity sensor 100 and an IC 110. The IC 110 is fixed onto the physical quantity sensor 100 by an adhesive member 45, and the structure 120 is fixed to the inner bottom surface 42a of the package 40 by an adhesive member 46.
[0014] The physical quantity sensor 100 includes a support substrate 10 , a lid 30 , and a terminal 17 , and is electrically connected to an IC 110 via a bonding wire 51 . 3, an X-axis acceleration sensor unit 100x, a Y-axis acceleration sensor unit 100y, and a Z-axis acceleration sensor unit 100z are provided between the support substrate 10 and the lid body 30. In this embodiment, the physical quantity sensor 100 is a triaxial acceleration sensor. The physical quantity sensor 100 may be a single-axis acceleration sensor or a biaxial acceleration sensor having one or two of the X-axis acceleration sensor unit 100x, the Y-axis acceleration sensor unit 100y, and the Z-axis acceleration sensor unit 100z, or a 6Dof (six degrees of freedom) sensor having a triaxial acceleration sensor unit and a triaxial angular velocity sensor unit.
[0015] The IC 110 generates and outputs an acceleration signal in the X-axis direction based on a signal output from the X-axis acceleration sensor unit 100x of the physical quantity sensor 100, an acceleration signal in the Y-axis direction based on a signal output from the Y-axis acceleration sensor unit 100y, and an acceleration signal in the Z-axis direction based on a signal output from the Z-axis acceleration sensor unit 100z. In this embodiment, the signals output from the X-axis acceleration sensor unit 100x, the Y-axis acceleration sensor unit 100y, and the Z-axis acceleration sensor unit 100z indicate the amount of change in capacitance, as will be described later.
[0016] The X-axis acceleration sensor unit 100x, the Y-axis acceleration sensor unit 100y, and the Z-axis acceleration sensor unit 100z each include a movable body 20 that moves in response to the magnitude of acceleration. Each movable body 20 is formed from a conductive silicon wafer substrate 20s, as will be described later.
[0017] In the following description, the configuration of the physical quantity sensor 100 will be described based on the configuration of the Z-axis acceleration sensor unit 100z. As shown in FIG. 4A or 4B, the Z-axis acceleration sensor unit 100z has a support substrate 10, a cover 30, and a movable body 20.
[0018] 1.1.1. Support substrate configuration The support substrate 10 is a glass substrate made of borosilicate glass, which is an insulating material, but may also be a silicon substrate or a ceramic substrate. The support substrate 10 has a recessed cavity 16 on the upper surface 10f.
[0019] The top surface 10f has a region 10fa along the periphery of the cavity 16. The region 10fa is a bonding region with the lid 30. The support substrate 10 is bonded to the lid 30 by a bonding material 18 provided in the region 10fa. In this embodiment, the bonding material 18 is a frit material.
[0020] A groove 10e is formed on the upper surface 10f along the region 10fa. The groove 10e is formed along the protective film 7 formed on the upper surface 10f in a manufacturing method of the physical quantity sensor 100, which will be described later. The bonding material 18 that has overflowed from the region 10fa flows into the groove 10e, and functions as a bank that prevents the bonding material 18 from overflowing beyond the groove 10e into the storage space s2. The protective film 7 will be described in detail in the section on the manufacturing method, which will be described later.
[0021] The support substrate 10 has, on an upper surface 16f within the cavity 16, fixed electrodes 11, 12, 13, support posts 14, and protrusions 15. The support posts 14 and protrusions 15 are formed integrally with the support substrate 10.
[0022] The fixed electrode 11 is provided on the negative side of the support 14 in the Y-axis direction, and overlaps with the first mass region 21 of the movable body 20 in plan view. The fixed electrode 12 is provided on the positive side of the support 14 in the Y-axis direction, and overlaps with the second mass region 22 of the movable body 20 in plan view. Fixed electrode 11 and fixed electrode 12 are detection electrodes that detect a change in capacitance occurring between them and movable body 20 .
[0023] Fixed electrode 13 is provided on the negative side of fixed electrode 11 in the Y-axis direction, on the positive side of fixed electrode 12 in the Y-axis direction, and between support columns 14 and 14 . On the negative side of the support 14 in the Y-axis direction, the fixed electrode 13 overlaps with the third mass region 23 and the first mass region 21 of the movable body 20 in a plan view. The portion of the fixed electrode 13 that overlaps with the first mass region 21 includes a portion that covers the protrusion 15.
[0024] On the positive side of the support 14 in the Y-axis direction, the fixed electrode 13 overlaps with the second mass region 22 of the movable body 20 in a plan view. The portion of the fixed electrode 13 that overlaps with the second mass region 22 includes a portion that covers the protrusion 15.
[0025] Fixed electrode 13 is a dummy electrode and is insulated from fixed electrodes 11 and 12 . The fixed electrode 13 is electrically connected to the movable body 20. Therefore, the fixed electrode 13 has the same potential as the movable body 20, and substantially no electrostatic attraction occurs between them. Therefore, the physical quantity sensor 100 of this embodiment can effectively prevent malfunction of the movable body 20 and sticking, in which the movable body 20 sticks to the protrusion 15.
[0026] The portion of the fixed electrode 13 that overlaps with the third mass region 23 of the movable body 20 is provided in a recess 16fc on the top surface 16f. The recess 16fc is a recessed portion on the top surface 16f, and is provided as a relief to prevent the end of the movable body 20 from colliding with it. The support pillar 14 supports the movable body 20 above the fixed electrodes 11 and 12 with a predetermined gap therebetween.
[0027] The protrusion 15 is a stopper that restricts the movable body 20 from swinging with an excessive amplitude, and prevents the end of the movable body 20 from colliding with the upper surface 16f of the support substrate . The protrusion 15 protrudes from the upper surface 16f of the support substrate 10 toward the positive side in the Z axis direction, and is provided so as to face the first mass region 21 and the second mass region 22 of the movable body 20.
[0028] 3 and 4A, four protrusions 15 are provided, one at each of two locations overlapping the first mass region 21 of the movable body 20 and two locations overlapping the second mass region 22 of the movable body 20. The number of locations where the protrusions 15 are provided is not limited to four. The protrusions 15 may be provided in two, six, eight or more locations.
[0029] Two protrusions 15 are provided along the extension direction of beam portion 25 of movable body 20. Beam portion 25 functions as a rotation axis or oscillation axis of movable body 20, and center line CL2 overlaps with the rotation axis or oscillation axis of movable body 20.
[0030] In this way, by providing multiple protrusions 15 along the extension direction of the beam portion 25 of the movable body 20, the physical quantity sensor 100 can disperse the impact when the movable body 20 and the protrusions 15 come into contact.
[0031] The centers of the two protrusions 15 provided on a straight line parallel to the center line CL2 are provided at positions at a distance R2 that are line-symmetrical with respect to the center line CL1 that divides the movable body 20 into two equal parts in the X-axis direction. In this way, by arranging the multiple protrusions 15 symmetrically with respect to the center line CL1, the physical quantity sensor 100 can prevent the posture of the movable body 20 from becoming unstable when the movable body 20 comes into contact with the protrusions 15.
[0032] The plurality of protrusions 15 are provided at positions symmetrical with respect to the center line CL2 at a distance R1. In this way, by arranging the multiple protrusions 15 line-symmetrically with respect to the center line CL2, the physical quantity sensor 100 can make the maximum swing angle of the first mass region 21 of the movable body 20 the same as the maximum swing angle of the second mass region 22 of the movable body 20. This can improve the accuracy of the physical quantity sensor 100. The swing angle can be rephrased as a rotation angle.
[0033] The protrusions 15 are provided at positions that do not overlap, in plan view, with perforated regions D1 in which the through-holes 26 of the movable body 20 are provided at predetermined intervals. In other words, the protrusions 15 are provided at positions that overlap, in plan view, with blank regions D2 in which the through-holes 26 of the movable body 20 are not provided.
[0034] Therefore, the movable body 20 comes into contact with the protrusion 15 in the blank area D2. Therefore, the contact of the movable body 20 with the protrusion 15 can prevent defects such as cracks, fissures, and chips from occurring in the movable body 20 starting from the edge of the through-hole 26.
[0035] 1.1.2. Lid structure The lid body 30 has a rectangular shape in plan view, similar to the support substrate 10. As shown in FIGS. 4A and 4B, the cover 30 has a cavity 31 formed as a recess on the underside.
[0036] The cavity 31 of the cover 30 and the cavity 16 of the support substrate 10 form a storage space s2. The movable body 20 is stored in the storage space s2. The cover 30 has a communication hole (not shown). After the desired atmosphere is created in the storage space s2 using the communication hole, the communication hole is closed, thereby sealing the movable body 20 in the storage space s2.
[0037] The storage space s2 is preferably filled with an inert gas such as nitrogen, helium, or argon, and is at approximately atmospheric pressure at the operating temperature (approximately -40°C to 80°C). By keeping the storage space s2 at atmospheric pressure, viscous resistance increases, a damping effect is exhibited, and vibration of the movable body 20 can be quickly converged or stopped.
[0038] In this embodiment, the lid 30 is a silicon substrate. The lid 30 is not limited to a silicon substrate. The lid 30 may be, for example, a glass substrate or a ceramic substrate. The lid 30 is preferably connected to ground, which makes it possible to keep the potential of the lid 30 constant and, for example, to reduce fluctuations in the capacitance between the lid 30 and the movable body 20.
[0039] The distance between the lower surface of cavity 31 and upper surface 20g of movable body 20 is preferably, for example, 15 μm or more, more preferably 20 μm or more, and even more preferably 25 μm or more. Such a distance can sufficiently reduce the capacitance between cover 30 and movable body 20, which is effective in improving the accuracy of acceleration detection.
[0040] 1.1.3.Configuration of moving body The movable body 20 is provided so as to be able to swing relative to the support substrate 10 . The movable body 20 is made of a conductive silicon substrate. By using a conductive silicon substrate for the movable body 20, it is possible to give the movable body 20 the function of an electrode. Note that a non-conductive substrate may be used for the movable body 20, and a conductive electrode layer may be formed on the lower surface 20f of the movable body 20.
[0041] The movable body 20 has a support portion 24 , a beam portion 25 , a through-hole 26 , and a conductive film 27 . The support portion 24 is connected to the support posts 14 of the support substrate 10 . Beam portion 25 is a rotation axis or oscillation axis of movable body 20. Beam portion 25 is supported by support portion 24, has a portion extending in the X-axis direction from support portion 24, and functions as a torsion spring.
[0042] The movable body 20 is supported on the support substrate 10 so as to be able to swing like a seesaw with the beam portion 25 as a fulcrum. The movable body 20 has a first movable part 20a and a second movable part 20b. The first movable portion 20a is the portion on the negative side of the center line CL2 in the Y-axis direction, and the second movable portion 20b is the portion on the positive side of the center line CL2 in the Y-axis direction. The first movable portion 20a has a first mass region 21, a third mass region 23, and a connecting region .
[0043] The second movable portion 20b has a second mass region 22 and a connecting region . The distance Ra from the center line CL2 to the end of the first movable part 20a is different from the distance Rb from the center line CL2 to the end of the second movable part 20b because the first movable part 20a has the third mass region 23. Therefore, the first movable part 20a and the second movable part 20b have different masses.
[0044] Because the mass of the first movable part 20a and the mass of the second movable part 20b are different, the rotational forces of the first movable part 20a and the second movable part 20b that are generated when acceleration in the Z-axis direction is applied to the movable body 20 are unbalanced. Therefore, when acceleration in the Z-axis direction is applied to the physical quantity sensor 100, the movable body 20 tilts. The physical quantity sensor 100 outputs the tilt of the movable body 20 as changes in the capacitances C1 and C2 via the fixed electrodes 11 and 12.
[0045] The changes in the capacitances C1 and C2 are monitored by the IC 110, which generates and outputs an acceleration signal in the Z-axis direction based on the changes in the capacitances C1 and C2.
[0046] The through-hole 26 is a through-hole that passes through the upper surface 20g and the lower surface 20f of the movable body 20 in the Z-axis direction. The through holes 26 are provided to reduce damping caused by the viscosity of gas when the movable body 20 oscillates. Damping is a function that tries to stop the movement of the movable body 20, and can be rephrased as flow resistance. In this way, by providing the through-hole 26 in the movable body 20, the physical quantity sensor 100 of this embodiment can improve the detection sensitivity of acceleration.
[0047] The movable body 20 has a perforated region D1 in which a plurality of through-holes 26 are provided at predetermined intervals, and a blank region D2 in which no through-holes 26 are provided. The size of the blank area D2 is, for example, a size equivalent to an area in the perforated area D1 where 2×2 through holes 26 are provided. The size of the perforated area D1 may be larger or smaller. The size of the perforated area D1 may be, for example, a size equivalent to an area in the perforated area D1 where 5×5 through holes 26 are provided.
[0048] The blank area D2 is provided in an area corresponding to the protrusion 15 of the support substrate 10. In this way, by making the area of the movable body 20 corresponding to the protrusion 15 the blank area D2, even if the movable body 20 comes into contact with the protrusion 15, the movable body 20 comes into contact with the protrusion 15 in the blank area D2, and therefore, the occurrence of defects such as cracks in the movable body 20 can be suppressed.
[0049] The conductive film 27 is provided in a blank area D2 on the lower surface 20f of the movable body 20 at a position that overlaps the protrusion 15 of the support substrate 10 in a plan view. In this manner, in this embodiment, the conductive film 27 and the protrusion 15 are provided so as to overlap with each other, thereby preventing the occurrence of sticking, in which the movable body 20 adheres to the protrusion 15.
[0050] In this embodiment, the planar shape of the conductive film 27 is a rounded rectangle with rounded corners, but the planar shape of the conductive film 27 is not limited to a rounded rectangle.
[0051] The planar shape of the conductive film 27 is larger than the protrusion 15 in plan view. In this way, by making the planar shape of the conductive film 27 larger than the protrusion 15, when the movable body 20 comes into contact with the protrusion 15, the conductive film 27 can be made to come into contact with the protrusion 15 without fail.
[0052] Furthermore, it is preferable that the planar shape of the conductive film 27 is as small as possible. For example, it is sufficient that the conductive film 27 is provided only in an area on the lower surface 20f of the movable body 20 where contact with the protrusion 15 is expected. This is because a smaller planar shape of the conductive film 27 can suppress an increase in the weight of the movable body 20, thereby suppressing a decrease in the sensitivity of the physical quantity sensor 100.
[0053] A fixed electrode 13 is provided on the protrusion 15 so as to cover the protrusion 15 . The fixed electrode 13 is a laminated film in which a plurality of conductive films are stacked. In this embodiment, the fixed electrode 13 is a two-layer laminated film in which the lower layer on the protrusion 15 side is made of titanium (Ti) and the upper layer on the conductive film 27 side is made of platinum (Pt).
[0054] The conductive film 27 is made of platinum. In other words, the conductive film 27 is made of the same material as the upper layer of the fixed electrode 13. In this way, by forming the conductive film 27 from the same material as the upper layer of the fixed electrode 13, the difference in work function between the conductive film 27 and the upper layer of the fixed electrode 13 can be made zero. Therefore, even if the conductive film 27 and the fixed electrode 13 come into contact with each other, the occurrence of contact electrification can be suppressed. Therefore, even if the movable body 20 comes into contact with the protrusion 15, the occurrence of sticking, in which the movable body 20 sticks to the protrusion 15, can be suppressed.
[0055] The conductive film 27 functions as a protective film that protects the lower surface 20f of the movable body 20 from etching that occurs when the through-hole 26 is formed. Therefore, the surface of the conductive film 27 is smoother than the lower surface 20f on which the conductive film 27 is not provided. Therefore, even if the movable body 20 comes into contact with the protrusion 15, sticking, in which the movable body 20 sticks to the protrusion 15, can be prevented.
[0056] 1.2. Manufacturing method of physical quantity sensor 5 to 22C are diagrams illustrating a method for manufacturing the physical quantity sensor 100 of this embodiment. FIG. 5 is a flowchart illustrating the manufacturing process of the physical quantity sensor 100. FIG. 6 is a flowchart showing details of the substrate preparation step S1 in FIG. 5. FIG. 7 is a flowchart showing details of the first substrate preparation step S11 in FIG. 6. FIG. 8 is a flowchart showing details of the second substrate preparation step S12 in FIG. 6. FIG. 9 is a flowchart showing details of the conductive film formation step S122 in FIG. 8. FIGS. 10 to 21 are cross-sectional views or plan views showing one embodiment of the manufacturing process, and the cross-sectional views show a cross section at a position corresponding to line DD in FIG. 11A. FIGS. 22A to 22C are plan views or cross-sectional views showing one embodiment of the manufacturing process according to a comparative example.
[0057] As shown in FIG. 5, the method for manufacturing the physical quantity sensor 100 includes a substrate preparation step S1, a lid preparation step S2, a sealing step S3, and a singulation step S4. In this embodiment, the substrate preparation step S1 is an example of a step of preparing a support substrate 10 as a substrate having a movable body 20, the lid preparation step S2 is an example of a step of preparing a lid body 30, and the sealing step S3 is an example of a step of sealing the movable body 20 between the support substrate 10 and the lid body 30. Note that in this embodiment, the physical quantity sensor 100 is manufactured in the form of a wafer and finally separated into individual pieces. Therefore, in each of steps S1, S2, S3, and S4, the glass wafer substrate 10s may be referred to as the support substrate 10, and the silicon wafer substrate 30s may be referred to as the lid body 30.
[0058] As shown in FIG. 6, the substrate preparation step S1 includes a first substrate preparation step S11, a second substrate preparation step S12, a bonding step S13, a movable body formation step S14, and a removal step S15. As shown in FIG. 7, the first substrate preparation step S11 includes a protrusion formation step S111, an electrode formation step S112, and a protective film formation step S113.
[0059] In the protrusion forming step S111, an etching mask is formed on the glass wafer substrate 10s, followed by wet etching to form cavities 16, support posts 14, and protrusions 15 on the glass wafer substrate 10s, as shown in Fig. 10. In this embodiment, the glass wafer substrate 10s is an example of a first substrate. In the protrusion forming step S111, cavities 161, 162 and support posts 141, 142 are formed in the X-axis acceleration sensor unit 100x and the Y-axis acceleration sensor unit 100y, as shown in Fig. 12A.
[0060] In the electrode formation process S112, as shown in Figures 11A and 11B, fixed electrodes 11, 12, and 13 made of laminated films of titanium and platinum are formed on the upper surface 16f of the cavity 16 and on the protrusion 15 using a wrist-off method.
[0061] 12A and 12B, in the protective film forming step S113, a protective film 7 is formed in the region 10fa surrounding the X-axis acceleration sensor unit 100x, the Y-axis acceleration sensor unit 100y, and the Z-axis acceleration sensor unit 100z. As described above, the support substrate 10 and the lid body 30 are bonded in the region 10fa. In this embodiment, the region 10fa is an example of a region where bonding with the lid body 30 is planned.
[0062] The protective film 7 functions as an etching stop layer that protects the region 10fa so that the region 10fa is not damaged by dry etching of the silicon wafer substrate 20s in a movable body forming step S14, which will be described later. In this embodiment, the protective film 7 is made of DLC (Diamond-like Carbon).
[0063] The inner corner 7a and the outer corner 7b of the protective film 7 are rounded. The R of the corner 7a of the protective film 7 has a roundness corresponding to the R of a corner 20ca of the countersunk groove 20c, which will be described later, and the R of the corner 7b has a roundness corresponding to the R of a corner 20cb of the countersunk groove 20c, which will be described later.
[0064] As shown in FIG. 8, the second substrate preparation step S12 includes a recess formation step S121 and a conductive film formation step S122. In the recess forming step S121, a countersunk groove 20c is formed in a silicon wafer substrate 20s, as shown in Fig. 13. In this step, a patterned resist mask is formed on the lower surface 20f of the silicon wafer substrate 20s, and etching is performed to form the countersunk groove 20c.
[0065] 17A and 17B, the countersunk groove 20c is provided at a position facing the protective film 7. Therefore, when the silicon wafer substrate 20s and the glass wafer substrate 10s are bonded together, the protective film 7 is disposed within the countersunk groove 20c. In other words, the protective film 7 does not contact the lower surface 20f of the silicon wafer substrate 20s.
[0066] In this way, the countersunk groove 20c prevents a gap or the like from occurring between the silicon wafer substrate 20s and the glass wafer substrate 10s, which would otherwise result in poor bonding, due to contact between the underside 20f of the silicon wafer substrate 20s and the protective film 7. In this embodiment, the countersunk groove 20c is an example of a recess facing the protective film 7.
[0067] An inner corner 20ca and an outer corner 20cb of the countersunk groove 20c are rounded so that the corners are rounded. In this embodiment, the R of the corner 20ca is a curve of a circle with a radius of 40 μm.
[0068] In this manner, in this embodiment, by rounding the corner 20ca of the countersunk groove 20c, the occurrence of defectively formed portions of the resist mask 4 at the inner corners of the corner 20ca of the countersunk groove 20c is suppressed. Since the occurrence of defectively formed portions of the resist mask 4 is suppressed, it is possible to suppress the formation of a residual film 27r made of the sputtered film 27s at the defectively formed portions of the resist mask 4 in the conductive film forming step S122 described later. The residual film 27r will be described in the comparative example section described later.
[0069] 9, the conductive film forming step S122 includes a resist mask forming step S1221, a film forming step S1222, and a resist mask removing step S1223, and uses a roll-off method to form a conductive film 27 on the lower surface 20f of the silicon wafer substrate 20s. The conductive film 27 is provided at a position overlapping the protrusion 15, as shown in FIGS. 17A and 17B.
[0070] 14, in the resist mask formation step S1221, resist is applied to the lower surface 20f of the silicon wafer substrate 20s and patterned to form a resist mask 4. As described above, the resist mask 4 is formed so as to cover all of the remaining areas on the lower surface 20f of the silicon wafer substrate 20s, except for only the positions where the conductive film 27 is to be provided. In other words, the resist mask 4 is reliably formed in the required areas, and no defective portions such as missing portions or insufficient film thickness occur.
[0071] In the film forming step S1222, a sputtered film 27s made of platinum is formed by sputtering on the resist mask 4 and the lower surface 20f of the silicon wafer substrate 20s, as shown in FIG.
[0072] In the resist mask removal step S1223, as shown in FIG. 16, the resist mask 4 is removed, and a patterned conductive film 27 is formed on the lower surface 20f of the silicon wafer substrate 20s.
[0073] As described above, in this embodiment, the occurrence of defective formation of the resist mask 4 at the inner corner of the corner 20ca of the countersunk groove 20c is suppressed. Therefore, the formation of a residual film 27r made of the sputtered film 27s at the inner corner of the corner 20ca of the countersunk groove 20c is suppressed. The residual film 27r formed at the inner corner of the corner 20ca of the countersunk groove 20c becomes a residue in the movable body forming step S14, and there is a risk that, for example, a bonding failure will occur due to foreign matter getting caught at the bonding surface. However, in this embodiment, the formation of the residual film 27r at the inner corner of the corner 20ca of the countersunk groove 20c is suppressed, and therefore the occurrence of a bonding failure due to the residue is also suppressed.
[0074] 6, in the bonding step S13, the glass wafer substrate 10s and the silicon wafer substrate 20s are bonded together. The glass wafer substrate 10s and the silicon wafer substrate 20s can be bonded together by, for example, anodic bonding.
[0075] As shown in FIGS. 17A and 17B, the glass wafer substrate 10s and the silicon wafer substrate 20s are combined and bonded together such that the protective film 7 is disposed inside the countersunk groove 20c.
[0076] Therefore, the protective film 7 is prevented from coming into contact with the lower surface 20f of the silicon wafer substrate 20s, thereby preventing a gap or the like from being generated between the glass wafer substrate 10s and the silicon wafer substrate 20s. As a result, the glass wafer substrate 10s and the silicon wafer substrate 20s are bonded in a good state.
[0077] In the movable body forming step S14, the movable body 20 is formed from a silicon wafer substrate 20s. In this process, first, as shown in FIG. 18, the silicon wafer substrate 20s is thinned, and then a hard mask 5 is formed. Next, the silicon wafer substrate 20s is thinned using a grinder and a polisher. Next, a silicon oxide (SiO2) film is formed on the upper surface 20g of the thinned silicon wafer substrate 20s, and then patterned to form the hard mask 5. Next, as shown in FIG. 19, the silicon wafer substrate 20s is dry-etched using the hard mask 5 to form the movable body 20.
[0078] By the dry etching in the movable body forming step S14, grooves 10e are formed on the upper surface 10f of the glass wafer substrate 10s along the outer and inner edges of the protective film 7. In the present embodiment, the step of dry etching the silicon wafer substrate 20s using the hard mask 5 is an example of a step of forming grooves 10e along the protective film 7.
[0079] Furthermore, the dry etching in the movable body forming step S14 damages and roughens the region 10fb of the upper surface 10f of the glass wafer substrate 10s, excluding the region 10fa where the protective film 7 is provided.
[0080] In the removal step S15, as shown in FIG. 20, the hard mask 5 and the protective film 7 are removed. In this step, first, the hard mask 5 on the movable body 20 is removed, and then the protective film 7 on the glass wafer substrate 10s is removed.
[0081] The surface of the region 10fa from which the protective film 7 has been removed remains smooth. In other words, the surface roughness of the region 10fa is smaller than the surface roughness of the region 10fb. As described above, the support substrate 10 and the lid body 30 are bonded to each other in the region 10fa. Therefore, by protecting the region 10fa from dry etching in the movable body forming step S14 by the protective film 7, the support substrate 10 and the lid body 30 can be bonded to each other well.
[0082] Returning to FIG. 5, in the lid preparation step S2, a cavity 31 is formed in the silicon wafer substrate 30s as shown in FIG. 21, the glass wafer substrate 10s and the silicon wafer substrate 30s are bonded together with a bonding material 18. In this embodiment, glass frit bonding is used to bond the glass wafer substrate 10s, the silicon wafer substrate 30s, and the frit material together.
[0083] In the sealing step S3, first, a frit material is sandwiched between the region 10fa of the glass wafer substrate 10s and the silicon wafer substrate 30s, and then they are heated and bonded in a frit furnace. After that, a desired atmosphere is created in the storage space s2 using a communication hole (not shown) provided in the glass wafer substrate 10s, and the communication hole is then closed, thereby sealing the movable body 20 in the storage space s2.
[0084] In the singulation step S4, the substrate is diced along the planned dividing lines v1 to form individual pieces. Each individual chip is selected in an inspection process (not shown), and only non-defective products are shipped as the physical quantity sensor 100. In this way, the physical quantity sensor 100 is obtained.
[0085] 1.2.1. Comparative Example Fig. 22A is a plan view showing one aspect of a manufacturing process according to a comparative example, illustrating a bottom surface 20f of a silicon wafer substrate 20s after removing the resist mask 4 in a resist mask removal step S1223. Fig. 22B is a cross-sectional view of the silicon wafer substrate 20s taken along line E-E in Fig. 22A.
[0086] 22A, in the comparative example, the corner 20ca of the countersunk groove 20c is angular. In other words, the corner 20ca is not rounded. Furthermore, as shown in FIGS. 22A and 22B, a residue film 27r is formed on the underside 20f of the silicon wafer substrate 20s at the inner corner of the corner 20ca.
[0087] FIG. 22C is a cross-sectional view illustrating one aspect of the manufacturing process according to the comparative example, showing bottom surface 20f of silicon wafer substrate 20s after sputtered film 27s made of platinum has been formed in film-forming step S1222.
[0088] 22C, a defective portion 4d where the resist mask 4 is missing occurs on the underside 20f of the silicon wafer substrate 20s at the inner corner of the corner portion 20ca. The sputtered film 27s formed in the defective portion 4d becomes the residual film 27r shown in FIGS. 22A and 22B.
[0089] As described above, the residual film 27r becomes a residue in the movable body forming step S14, and causes bonding defects due to foreign matter getting caught in the bonding surface, for example. In contrast, in this embodiment, the corner 20ca of the countersunk groove 20c is rounded by adding R. This prevents the residue film 27r from being formed on the inner corner of the corner 20ca of the countersunk groove 20c, thereby preventing bonding defects caused by the residue film 27r.
[0090] As described above, the manufacturing method of the physical quantity sensor 100 of this embodiment includes the support substrate 10 as a substrate having the movable body 20, the lid body 30, and the bonding material 18 that bonds the support substrate 10 and the lid body 30, and includes a substrate preparation step S1 as a step of preparing the support substrate 10, a lid body preparation step S2 as a step of preparing the lid body 30, and a sealing step S3 as a step of bonding the support substrate 10 and the lid body 30 via the bonding material 18 to seal the movable body 20 between the support substrate 10 and the lid body 30. The substrate preparation step S1 as a step of preparing the support substrate 10 includes a step of bonding the support substrate 10 to the lid body 30 in a planned region where the lid body 30 is to be bonded. In the entire region 10fa, the process includes a first substrate preparation step S11 for preparing a glass wafer substrate 10s as a first substrate having a protective film 7; a second substrate preparation step S12 for preparing a silicon wafer substrate 20s as a second substrate having a countersunk groove 20c as a recess facing the protective film 7; a bonding step S13 for bonding the glass wafer substrate 10s and the silicon wafer substrate 20s so that the protective film 7 is disposed in the countersunk groove 20c; a movable body formation step S14 for etching the silicon wafer substrate 20s to form the movable body 20; and a removal step S15 for removing the protective film 7.
[0091] As described above, in this embodiment, the region 10fa of the glass wafer substrate 10s, which is a region to be bonded to the lid body 30, is protected by the protective film 7 before the movable body forming step S14, and is removed after the movable body forming step S14. Therefore, the surface of the region 10fa is not damaged by etching and remains smooth, allowing for good bonding between the support substrate 10 and the lid body 30.
[0092] Furthermore, the silicon wafer substrate 20s is provided with a countersunk groove 20c facing the protective film 7, and the glass wafer substrate 10s and the silicon wafer substrate 20s are bonded together so that the protective film 7 is disposed in the countersunk groove 20c. Therefore, even if the protective film 7 is formed, the movable body forming step S14 can be carried out without any problems.
[0093] In the manufacturing method of the physical quantity sensor 100 of this embodiment, the first substrate preparation process S11 includes a protrusion formation process S111 for forming protrusions 15 on a glass wafer substrate 10s as the first substrate, and the second substrate preparation process S12 includes a conductive film formation process S122 for providing a conductive film 27 that overlaps the protrusions 15 in a planar view on a silicon wafer substrate 20s as the second substrate.
[0094] As described above, this embodiment includes a step of providing the silicon wafer substrate 20s with a conductive film 27 that overlaps the protrusion 15 in a plan view. Therefore, when the movable body 20 swings excessively, the conductive film 27 of the movable body 20 comes into contact with the protrusion 15. Therefore, even if the movable body 20 swings excessively and comes into contact with the protrusion 15, it is possible to prevent sticking, in which the movable body 20 sticks to the protrusion 15.
[0095] In the manufacturing method of the physical quantity sensor 100 of this embodiment, the first substrate preparation process S11 includes a protrusion formation process S111 as a process of forming a protrusion 15 on a glass wafer substrate 10s as the first substrate, and the second substrate preparation process S12 includes a recess formation process S121 as a process of forming a countersunk groove 20c as a recess on a silicon wafer substrate 20s as the second substrate so that corners 20ca of two intersecting sides of the countersunk groove 20c are rounded, and a conductive film formation process S122 as a process of providing a conductive film 27 that overlaps the protrusion 15 in a planar view on the silicon wafer substrate 20s, and the conductive film formation process S122 includes a resist mask formation process S1221 as a process of forming a resist mask 4 on the silicon wafer substrate 20s, a film formation process S1222 as a process of forming a sputtered film 27s as a conductive member so as to cover the resist mask 4, and a resist mask removal process S1223 as a process of removing the resist mask 4.
[0096] As described above, in this embodiment, the countersunk groove 20c is formed so that the corner 20ca thereof is rounded. Therefore, the formation of the residual film 27r at the inner corner of the corner 20ca is suppressed. Therefore, the residual film 27r is suppressed from becoming a residue in the movable body forming step S14, and therefore, the occurrence of poor bonding due to foreign matter getting caught in the bonding surface between the support substrate 10 and the lid body 30 can be suppressed.
[0097] In the manufacturing method of the physical quantity sensor 100 of this embodiment, the first substrate preparation step S11 includes a protective film formation step S113 as a step of forming the protective film 7 so that the corners 7a of two intersecting sides of the protective film 7 are rounded.
[0098] In this manner, in this embodiment, the protective film 7 is formed so that its corners 7a are rounded, thereby enabling good bonding between the glass wafer substrate 10s and the silicon wafer substrate 20s.
[0099] In the manufacturing method of the physical quantity sensor 100 of this embodiment, the movable body forming step S14 includes a step of forming a groove 10e along the protective film 7 in a glass wafer substrate 10s as a first substrate.
[0100] As described above, in this embodiment, the glass wafer substrate 10s has the groove 10e formed along the protective film 7. Therefore, even if the bonding material 18 overflows from the region 10fa, the overflowing bonding material 18 flows into the groove 10e, and therefore the overflow of the bonding material 18 is suppressed compared to when the groove 10e is not provided. Therefore, the risk that the bonding material 18 will spread to the region 10fb and affect the surrounding components is suppressed.
[0101] 2. Embodiment 2 2.1.Inertial Measurement Unit Overview FIG. 23 is an explanatory diagram of a sensor module 300 as an inertial measurement unit (IMU) equipped with a physical quantity sensor 100.
[0102] FIG. 23 is an exploded perspective view showing a schematic configuration of the sensor module 300. As shown in FIG. The sensor module 300 is mounted on a wearable device such as an automobile, a robot, a smartphone, or a portable activity monitor, and is used as a device for detecting the posture, behavior, etc. of the wearable device.
[0103] As shown in FIG. 23, the sensor module 300 includes an outer case 301, a joining member 310, and a sensor unit 325, and is configured such that the sensor unit 325 is fitted or inserted into the interior 303 of the outer case 301 with the joining member 310 interposed therebetween.
[0104] Outer case 301 is a box-like container with a rectangular parallelepiped exterior and no lid, and its interior 303 is an internal space surrounded by wall surface 304, bottom surface 305, and joint surface 306. Outer case 301 is made of aluminum, for example. The material of outer case 301 may also be other metals such as zinc or stainless steel, resin, or a composite material of metal and resin.
[0105] The outer shape of the outer case 301 is a rectangular parallelepiped with a substantially square planar shape, and through-holes 302 are formed near each of two vertices located diagonally across the square. The sensor module 300 is attached to the device to be mounted using the through-holes 302 by screwing or the like.
[0106] The sensor unit 325 includes an inner case 320 and a substrate 315 . The substrate 315 mounts the physical quantity sensor device 1 incorporating the physical quantity sensor 100, a connector 316 for external connection, and the like.
[0107] Inner case 320 supports substrate 315 and is housed inside 303 of outer case 301. The thickness of inner case 320, in other words, the height in the Z-axis direction, is equal to or smaller than the height from top surface 307 of outer case 301 to joint surface 306. The same material as that of outer case 301 can be used for inner case 320. The bottom surface of the inner case 320 is formed with a recess 331 for preventing contact with the physical quantity sensor device 1 and an opening 321 for exposing the connector 316 .
[0108] 2.2.Outline of the board FIG. 24 is a perspective view of a substrate 315 on which the physical quantity sensor 100 is mounted. 24, the physical quantity sensor device 1, a connector 316, and angular velocity sensors 317x, 317y, and 317z are mounted on the top and side surfaces of the substrate 315. A control IC 319 is mounted on the bottom surface of the substrate 315. The substrate 315 is a multi-layer substrate with a plurality of through holes formed therein. The substrate 315 is a glass epoxy substrate. The substrate 315 may also be a rigid substrate such as a composite substrate or a ceramic substrate.
[0109] The physical quantity sensor device 1 includes a physical quantity sensor 100, an IC 110, and a package 40. The connector 316 is a plug-type connector and has two rows of connection terminals arranged at equal pitches in the X-axis direction. In this embodiment, the connector has two rows of connection terminals with 10 pins per row, for a total of 20 pins, but the number of connection terminals may be changed as appropriate depending on the design specifications.
[0110] The angular velocity sensor 317z is a gyro sensor that detects a uniaxial angular velocity in the Z-axis direction. The angular velocity sensor 317z is preferably a vibration gyro sensor that uses a quartz crystal as an oscillator and detects the angular velocity from the Coriolis force acting on a vibrating object. The oscillator is not limited to a quartz crystal, and may be one that uses ceramic or silicon.
[0111] Angular velocity sensor 317x that detects angular velocity along one axis in the X-axis direction is mounted on a side surface of substrate 315 in the X-axis direction, with the mounting surface perpendicular to the X-axis. Similarly, angular velocity sensor 317y that detects angular velocity along one axis in the Y-axis direction is mounted on a side surface of substrate 315 in the Y-axis direction, with the mounting surface perpendicular to the Y-axis.
[0112] The angular velocity sensors 317x, 317y, and 317z are not limited to a configuration using one angular velocity sensor for each axis, for a total of three, but any sensor capable of detecting angular velocity on three axes may be used. For example, a sensor device capable of detecting angular velocity on three axes in one device or package may be used.
[0113] The physical quantity sensor device 1 is an acceleration sensor for measuring acceleration in the Z-axis direction, but may also measure acceleration in the X-axis direction or the Y-axis direction. The physical quantity sensor device 1 may be equipped with a physical quantity sensor 100 that measures acceleration in the X-axis and / or Y-axis directions, and may detect acceleration in the Z-axis and Y-axis directions, the Z-axis and X-axis directions, or in the three XYZ-axis directions.
[0114] The control IC 319 is an MCU (Micro Controller Unit) that has built-in storage including non-volatile memory, and arithmetic circuits that perform temperature correction processing and alignment correction processing, and is a control unit that controls each part of the sensor module 300.
[0115] The memory unit stores a program that defines the order and content for detecting acceleration and angular velocity, a program that digitizes the detection signals and incorporates them into packet data, and accompanying data, etc. The board 315 also has multiple electronic components mounted thereon, such as a temperature sensor.
[0116] According to such a sensor module 300, since the physical quantity sensor device 1 equipped with the physical quantity sensor 100 is used, it is possible to provide a sensor module 300 that is excellent in impact resistance and has improved reliability.
[0117] As described above, according to the sensor module 300 as an inertial measurement unit including the physical quantity sensor 100 of this embodiment, in addition to the effects of the first embodiment, it is possible to provide a highly reliable inertial measurement unit.
[0118] Although the preferred embodiment has been described above, the present invention is not limited to the above embodiment. The configuration of each part of the present invention can be replaced with any configuration that exhibits the same function as the above embodiment. [Explanation of symbols]
[0119] 1...physical quantity sensor device, 4...resist mask, 4d...defective formation area, 5...hard mask, 7...protective film, 7a, 7b...corner, 10...support substrate, 10e...groove, 10f...upper surface, 10fa, 10fb...area, 10s...glass wafer substrate, 11, 12, 13...fixed electrode, 14, 141, 142...support, 15...protrusion, 16, 161, 162...cavity, 16f...upper surface, 16fc...recess, 17...terminal, 18...bonding material, 20...movable body, 20a...first Movable part, 20b...second movable part, 20c...counterbore groove, 20ca, 20cb...corner part, 20f...lower surface, 20g...upper surface, 20s...silicon wafer substrate, 21...first mass region, 22...second mass region, 23...third mass region, 24...support part, 25...beam part, 26...through hole, 27...conductive film, 27s...sputtered film, 27r...residue film, 28...connecting region, 30...lid, 30s...silicon wafer substrate, 31...cavity, 40...package, 41...lid, 42...base part, 42a...inner bottom surface, 42b...lower surface, 43...castellation, 44...sealing member, 45, 46...adhesive member, 51, 52...bonding wire, 53...terminal, 54...electrode pad, 100...physical quantity sensor, 100x...X-axis acceleration sensor part, 100y...Y-axis acceleration sensor part, 100z...Z-axis acceleration sensor part, 110...IC, 120...structure, 300...sensor module, 301...outer case, 302...through hole, 303...interior, 304...wall surface, 305...bottom surface, 306...joint surface, 307...top surface, 310...jointing member, 315...board, 316...connector, 317x, 317y, 317z...angular velocity sensor, 319...control IC, 320...inner case, 321...opening, 325...sensor unit, 331...recess, C1, C2...capacitance, CL1...center line, CL2...center line, D1...perforated area, D2...blank area, R1, R2...distance, v1...planned division line, s1, s2...storage space.
Claims
1. A method for manufacturing a physical quantity sensor having a substrate having a movable body, a lid, and a bonding material that bonds the substrate and the lid, comprising: providing the substrate; providing the lid; and joining the substrate and the lid body via the bonding material to seal the movable body between the substrate and the lid body, The step of preparing the substrate includes: preparing a first substrate having a protective film in a region where the lid is to be bonded; preparing a second substrate having a recess facing the protective film; bonding the first substrate and the second substrate together so that the protective film is disposed in the recess; Etching the second substrate to form the movable body; removing the protective film. A method for manufacturing a physical quantity sensor.
2. the step of preparing the first substrate includes a step of forming a protrusion on the first substrate; the step of preparing the second substrate includes a step of providing a conductive film on the second substrate that overlaps with the protrusion in a plan view; A method for manufacturing the physical quantity sensor according to claim 1 .
3. the step of preparing the first substrate includes a step of forming a protrusion on the first substrate; The step of preparing the second substrate includes: forming the recess in the second substrate so that corners of two intersecting sides of the recess are rounded; providing a conductive film on the second substrate that overlaps the protrusion in a plan view; The step of providing a conductive film includes: forming a resist mask on the second substrate; forming a conductive member to cover the resist mask; and removing the resist mask. A method for manufacturing the physical quantity sensor according to claim 1 .
4. The step of preparing the first substrate includes a step of forming the protective film so that corners of two intersecting sides of the protective film are rounded. The method for manufacturing the physical quantity sensor according to claim 3 .
5. the step of forming the movable body includes the step of forming a groove along the protective film in the first substrate. A method for manufacturing the physical quantity sensor according to claim 1 .
Citation Information
Patent Citations
Functional element, method for manufacturing functional element, electronic apparatus and mobile body
JP2018169365A