Inertial force sensor and method for manufacturing the same

Abstract

To provide an inertial force sensor including a glass vibrator that is hermetically sealed in a highly evacuated package.SOLUTION: An inertial force sensor includes a package that is configured to be hermetically sealed with a lid. The inertial force sensor includes a glass substrate stored in the package. The back surface of the glass substrate is adhesively fixed to a mounting surface in the package. The inertial force sensor includes an electrode portion disposed on the front surface of the glass substrate. The inertial force sensor includes a glass oscillator including a tubular pillar portion having a central axis, and an approximately hemispherical hollow peripheral portion centered on the central axis. The glass oscillator has a pillar portion fixed to the electrode portion. A groove is formed in at least one of the back surface of the glass substrate and the mounting surface of the package. A die bond material is disposed between the back surface and the mounting surface.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] This specification relates to an inertial force sensor and a method for manufacturing the inertial force sensor.

Background Art

[0002] Patent Document 1 discloses a Bird-bath Resonator Gyroscope (BRG) using a glass vibrator made of fused silica as a gyro sensor capable of achieving high precision. The glass vibrator is hermetically sealed in a package. The higher the degree of vacuum, the more the inhibitory factors that attenuate the vibration energy of the glass vibrator can be reduced, so that a gyro sensor with higher precision can be realized.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to store the glass vibrator in a package, an electrode substrate laminated with a glass substrate and a semiconductor substrate is used. The glass vibrator is fixed to the electrode substrate. The back surface of the glass substrate is adhesively fixed to the mounting surface in the package by a die bonding material. Gas is discharged from this die bonding material. However, if the gas cannot be sufficiently discharged from the die bonding material, outgassing may occur from the die bonding material after hermetic sealing. It becomes difficult to achieve a high vacuum inside the package or to maintain a high vacuum state.

Means for Solving the Problems

[0005] The inertial force sensor disclosed in this specification includes a package that can be hermetically sealed by a lid. The inertial force sensor includes a glass substrate stored in the package. The back surface of the glass substrate is adhesively fixed to the mounting surface in the package. The inertial force sensor includes an electrode portion disposed on the surface of the glass substrate. The inertial force sensor includes a glass vibrator having a tubular column portion with a central axis and a hollow substantially hemispherical peripheral portion centered on the central axis. In the glass vibrator, the column portion is fixed to the electrode portion. A groove is formed in at least one of the back surface of the glass substrate and the mounting surface of the package. A die bond material is disposed between the back surface and the mounting surface.

[0006] According to the above structure, the gas released from the inside of the die bond material can be efficiently discharged to the outside of the die bond material through the groove. Since the gas can be sufficiently discharged from the die bond material, it is possible to suppress the outgassing generated from the die bond material after vacuum hermetic sealing. It becomes possible to achieve a high vacuum inside the package and maintain the high vacuum state.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

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Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Mode for Carrying Out the Invention

Example

[0008] FIG. 1 shows a top view of the gyro sensor 1 according to this example. In FIG. 1, for ease of viewing, the state where the lid 130 is removed is shown. Also, FIG. 2 shows a cross-sectional view taken along line II-II. FIG. 2 is a cross-sectional view passing through the central axis CA. The gyro sensor 1 includes a sensor element 10 and a package 100. The sensor element 10 is hermetically sealed in the package 100.

[0009] (Configuration of the sensor element 10) FIG. 3 shows an enlarged cross-sectional view of the sensor element 10. FIG. 3 is a view obtained by enlarging the vicinity of the sensor element 10 in the cross-sectional view of FIG. 2. The sensor element 10 mainly includes a pedestal electrode 20, a glass oscillator 30, and a paste 40. The pedestal electrode 20 has a structure in which a silicon substrate 22 is laminated on a glass substrate 21.

[0010] Figure 4 shows a bottom view of the glass substrate 21. The glass substrate 21 has a rectangular shape when viewed from a direction (z - direction) perpendicular to the glass substrate 21. A plurality of grooves 21t are formed on the back surface 21b of the glass substrate 21. Since the shape and function of each of the plurality of grooves 21t are common, hereinafter, there may be a description of one representative groove 21t. The glass substrate 21 includes a side 21y parallel to the y - axis and a side 21x parallel to the x - axis. The groove 21t is parallel to the side 21y. That is, the groove 21t extends parallel to the y - axis. The groove 21t intersects the side 21x located on the outer periphery of the glass substrate 21. In other words, the groove 21t reaches the ends of the glass substrate 21 in the ±y direction.

[0011] The cross - sectional shape of the groove 21t may be various. In this embodiment, as shown in FIG. 3, the cross - section of the groove 21t has a round shape. This is because, as will be described later, the groove 21t is formed by isotropic wet etching. The groove 21t has a depth D1 and a width W1. The depth of the groove 21t may be 10 μm or less, for example, about 1 - 2 μm.

[0012] Here, focus on the central region R1 of the glass substrate 21. The central region R1 is a region located near the center of the glass substrate 21. The method for determining the central region R1 in this embodiment will be described. The rectangular shape of the glass substrate 21 is divided into nine rectangular shapes having the same shape as each other. And the region occupied by one rectangular shape located at the center thereof is defined as the central region R1. Also, the region occupied by the eight rectangular shapes surrounding the central region R1 is defined as the outer peripheral region R2. The density of the plurality of grooves 21t formed in the central region R1 is higher than that in the outer peripheral region R2.

[0013] The silicon substrate 22 includes an annular electrode 22c, a plurality of divided electrodes 22d, and an outer peripheral electrode 22o. The annular electrode 22c is disposed on the surface 21f of the glass substrate 21. The annular electrode 22c has a cylindrical shape around the central axis CA and has a through hole 22h. The central axis CA passes through the center of the glass substrate 21 and is an axis perpendicular to the surface 21f. The plurality of divided electrodes 22d are rotationally symmetrically arranged on a circumference centered on the central axis CA. The plurality of divided electrodes 22d surround the annular electrode 22c. An electrode pad 23 is formed on each of the plurality of divided electrodes 22d. An annular ring through portion 22r is formed between the outer periphery of the annular electrode 22c and the inner periphery of the plurality of divided electrodes 22d. The rim portion 30r of the glass oscillator 30 is inserted into the ring through portion 22r. The outer peripheral electrode 22o surrounds the divided electrodes 22d. The outer peripheral electrode 22o is connected to the annular electrode 22c by four wirings 25. In this embodiment, the wiring 25 is formed of an Al film. BR pads 24 are arranged at the four corners of the outer peripheral electrode 22o.

[0014] The glass oscillator 30 includes a column portion 30p and a peripheral portion 30c. The column portion 30p is a tubular portion having the central axis CA. The peripheral portion 30c is a hollow substantially hemispherical portion centered on the central axis CA. As shown in FIG. 3, the cross-sectional shape of the glass oscillator 30 in a plane passing through the central axis CA is substantially M-shaped. The material of the glass oscillator 30 is fused silica (quartz).

[0015] A conductive film (not shown) is formed on the surface of the glass oscillator 30. Various materials can be used for the conductive film. In this embodiment, the conductive film is a TiN film. The conductive film can be formed to have a nano-level thickness by film formation by ALD (Atomic Layer Deposition). The thickness of the conductive film can be, for example, in the range of 5 - 30 nm. In this embodiment, the thickness is 10 nm.

[0016] The quartz resonator 30 is fixed to the annular electrode 22c such that the central axis CA of the column portion 30p coincides with the central axis CA of the annular electrode 22c. Specifically, the bottom of the column portion 30p is adhered to the annular electrode 22c by the paste 40. The paste 40 is a so-called conductive paste. The material form of the paste 40 is the same as that of the die bond material 50 described later. The paste 40 electrically connects the conductive film on the surface of the quartz resonator 30 and the annular electrode 22c. The annular electrode 22c is connected to the BR pad 24 via the wiring 25 and the outer peripheral electrode 22o. Therefore, the conductive film on the surface of the quartz resonator 30 and the BR pad 24 are electrically connected.

[0017] (Arrangement mode of the die bond material 50) As shown in FIG. 3, a die bond material 50 is disposed between the back surface 21b of the glass substrate 21 and the mounting surface 101 of the package 100. The die bond material 50 is a conductive material used to adhesively fix the glass substrate 21 to the mounting surface 101. The die bond material 50 is a material that hardens by applying heat and exhibits conductivity. Various materials can be used for the die bond material 50. For example, it may be a paste material (Ag paste) in which Ag particles are mixed with an organic material of a binder. When heat is applied to the Ag paste, the binder sublimes and Ag hardens, exhibiting an adhesive function and conductivity.

[0018] The die bond material 50 has entered from the opening of the groove 21t to the inner side of the groove 21t. A space SP is formed by the void remaining between the entering die bond material 50 and the bottom surface 21tm of the groove 21t.

[0019] FIG. 5 illustrates the arrangement pattern of the die bond region DR when viewed from a direction (z direction) perpendicular to the glass substrate 21. In FIG. 5, for clarity, only the glass substrate 21, the die bond region DR, and the package 100 are shown. The die bond region DR is a region where the die bond material 50 exists and is a region formed within the glass substrate 21. FIG. 5 shows an example in which the die bond region DR is arranged over the entire area where the glass substrate 21 is disposed. Also in FIG. 5, the outer peripheral contour of the die bond region DR is indicated by a dotted line. The outer periphery of the glass substrate 21 and the outer peripheral contour of the die bond region DR are substantially coincident.

[0020] As described with reference to FIG. 4, the plurality of grooves 21t reach the side 21x of the glass substrate 21 in the ±y direction. That is, the plurality of grooves 21t intersect the outer periphery of the glass substrate 21 and also intersect the outer peripheral contour of the die bond region DR.

[0021] (Configuration of Package 100) The configuration of the package 100 will be described with reference to FIGS. 1 and 2. The package 100 is configured to be hermetically sealed by a lid 130. A metal mounting surface 101 is disposed on the bottom surface inside the package 100. The mounting surface 101 is a surface on which the sensor element 10 is fixed by the die bond material 50.

[0022] A plurality of electrodes 102 are arranged so as to surround the mounting surface 101. A plurality of electrode pads 23 provided on the sensor element 10 are connected to the corresponding electrodes 102 by wire bonds 110. In this embodiment, the wire bonds 110 are made of Au wires. Also, as shown in FIG. 2, a plurality of pads 102p are disposed outside the package 100. The plurality of pads 102p correspond to each of the plurality of electrodes 102 and are connected to each of the plurality of electrodes 102. The gyro sensor 1 can be connected to an external control circuit (not shown) via the plurality of pads 102p.

[0023] A rectangular frame 103 is arranged on the outer periphery of a plurality of electrodes 102. The frame 103 only needs to be an insulator, and various materials (e.g., ceramics) can be used. A seal portion 120 is arranged on the upper surface of the frame 103. The seal portion 120 includes a lower electrode frame 121, a seal ring 122, and an upper electrode frame 123. The lower electrode frame 121 is arranged on the upper surface of the frame 103. The upper electrode frame 123 is arranged on the lower surface of the lid 130. The lower electrode frame 121, the seal ring 122, and the upper electrode frame 123 are all in a rectangular frame shape, and their formation positions correspond to each other. The materials and thicknesses of the lower electrode frame 121, the seal ring 122, and the upper electrode frame 123 may vary. In this embodiment, the lower electrode frame 121 is an Au / Ni film, and the upper electrode frame 123 is an Au / Cr film. The seal ring 122 is made of AuSn with a thickness of about 100 μm.

[0024] The lid 130 is joined to the frame 103 by the seal portion 120. Thereby, the inside of the package 100 can be hermetically sealed. The material of the lid 130 is glass (e.g., borosilicate glass).

[0025] (Operation of the gyro sensor 1) A capacitor is formed between each of the plurality of divided electrodes 22d and the glass vibrator 30. An electrical signal is applied to the plurality of divided electrodes 22d from an external control circuit (not shown) via the plurality of pads 102p. By generating an electrostatic attraction force between the glass vibrator 30 and the plurality of divided electrodes 22d, the glass vibrator 30 is excited in a wine glass mode at the resonance frequency. When an angular velocity ωz is applied around the z-axis in this state, a Coriolis force is generated. Then, an amplitude corresponding to the generated Coriolis force is generated in the detection direction. The generated amplitude can be detected by a change in the capacitance of the capacitor formed between the divided electrode 22d and the glass vibrator 30. From the above, the gyro sensor 1, which is an inertial force sensor, functions.

[0026] (Manufacturing method of the gyro sensor 1) Fig. 6 shows a flowchart outlining the manufacturing process of the gyro sensor 1. In the glass molding step S1, the glass resonator 30 is molded from a fused silica (quartz) plate using a flame and a mold. In the groove forming step S2 of the glass substrate, a groove 21t is formed on the back surface 21b of the glass substrate 21 by etching. In the pedestal electrode manufacturing step S3, the glass substrate 21 and the silicon substrate 22 are joined to produce the pedestal electrode 20.

[0027] In the pedestal electrode mounting step S4, the pedestal electrode 20 is adhered to the mounting surface 101 of the package 100 with a die bond material 50. In the glass resonator mounting step S5, the glass resonator 30 is fixed to the pedestal electrode 20 with a paste 40. In the vacuum hermetic sealing step S6, the package 100 with the glass resonator 30 and the pedestal electrode 20 mounted is hermetically sealed in a vacuum. Through the above six steps, a glass resonator gyro sensor is manufactured. Each step will be described in detail below.

[0028] The glass molding step S1 will be described. First, a quartz plate is melt-molded using a glass molding apparatus. The specific details of the melt molding are omitted. The quartz plate with the glass resonator part formed is removed from the mold. The glass resonator 30 is taken out from the quartz plate using CMP (Chemical Mechanical Polishing) or the like. Finally, a thin conductive film is formed on the surface of the glass resonator 30 by ALD. A film is uniformly formed on the inner and outer surfaces of the glass, imparting conductivity to the glass resonator 30.

[0029] The groove forming step S2 of the glass substrate will be described. Figs. 7 and 8 show cross-sectional views of the glass substrate 21. As shown in Fig. 7, a resist layer 60 is applied to the back surface 21b of the glass substrate 21. Then, using well-known photolithography technology, a plurality of opening patterns 60p corresponding to the plurality of grooves 21t are formed in the resist layer 60.

[0030] Next, the back surface 21b is wet-etched through a plurality of opening patterns 60p. In this embodiment, a buffered hydrofluoric acid solution was used as the etching solution. As a result, as shown in FIG. 8, a plurality of grooves 21t can be formed. Since the wet etching is isotropic etching, the cross-sectional shape of the groove 21t is a round shape. Also, etching progresses in the portion masked by the resist layer 60, resulting in an undercut. Therefore, the width W1 of the groove 21t becomes larger than the opening width W2 of the opening pattern 60p. Note that the depth D1 of the groove 21t can be controlled by managing the etching time. Finally, the resist layer 60 is peeled off and the glass substrate 21 is cleaned.

[0031] The manufacturing process of the pedestal electrode in step S3 will be described. FIGS. 9 to 11 show cross-sectional views of the glass substrate 21 and the silicon substrate 22. As shown in FIG. 9, a resist layer 61 having an opening pattern 61p is formed on the surface 21f of the glass substrate 21. The surface 21f is wet-etched through the opening pattern 61p. Thereby, a ring groove 21r can be formed.

[0032] Next, the resist layer 61 is peeled off. An Al thin film is formed on the surface 21f, and the wiring 25 (see FIG. 1) is formed by a well-known patterning technique. Thereafter, as shown in FIG. 10, the silicon substrate 22 is anodically bonded to the surface 21f. Since a well-known technique can be used for anodic bonding, a detailed description thereof will be omitted. In this embodiment, as the conditions for anodic bonding, a temperature of 350° C. and an applied voltage of -700V to -1000V were used.

[0033] An Al thin film is formed on the surface 22f of the silicon substrate 22, and the electrode pad 23 and the BR pad 24 are formed by a well-known patterning technique. Thereafter, a resist layer 62 having an opening pattern 62p is formed on the surface 22f. Thereby, the structure shown in FIG. 10 is completed.

[0034] Through the opening pattern 62p, the silicon substrate 22 is trench-etched by DRIE (Deep Reactive Ion Etching) technology. As a result, as shown in FIG. 11, the annular electrode 22c, the split electrode 22d, and the outer peripheral electrode 22o are formed. In addition, the ring groove 21r and the wiring 25 previously formed on the glass substrate 21 can be exposed. Thus, the pedestal electrode 20 is completed.

[0035] The mounting process of the pedestal electrode in step S4 will be described. The die bonding material 50 is applied to the mounting surface 101 of the package 100. In this embodiment, the die bonding material 50 is applied to the entire die bonding region DR shown in FIG. 5. The back surface 21b of the pedestal electrode 20 fabricated in step S3 is pressed against the applied die bonding material 50. At this time, as shown in FIG. 5, the outer periphery of the glass substrate 21 and the outer peripheral contour of the die bonding region DR are positioned so as to substantially coincide.

[0036] When the pedestal electrode 20 is pressed, the die bonding material 50 penetrates into the inside of the groove 21t. The amount of penetration of the die bonding material 50 into the groove 21t can be appropriately controlled by the pressing pressure of the pedestal electrode 20. Then, a space SP is formed between the penetrated die bonding material 50 and the bottom surface 21tm of the groove 21t (see FIG. 3). The space SP functions as a discharge path for the outgas generated from the die bonding material 50.

[0037] While the pedestal electrode 20 is being pressed, heat treatment is performed. In this embodiment, it is heated at 280 °C for 30 minutes or more. By baking and solidifying the die bonding material 50 in this way, the pedestal electrode 20 can be fixed to the package 100. In addition, heat treatment can promote the generation of outgas from the die bonding material 50. And the space SP formed in the groove 21t is not blocked by this heat treatment either. Therefore, the space SP can function as a discharge path for the outgas generated from the die bonding material 50. It becomes possible to efficiently discharge the outgas generated by heat in the vicinity of the center of the die bonding region DR using the space SP.

[0038] Describe the implementation process of the glass resonator in step S5. First, apply paste 40 inside the annular electrode 22c at the center of the pedestal electrode 20.

[0039] Hold the glass resonator 30 fabricated in the aforementioned glass molding process (step S1) with a collet (not shown). Then, insert the bottom surface of the column portion 30p into the inside of the annular electrode 22c so that the central axis CA of the column portion 30p coincides with the central axis CA of the annular electrode 22c. The paste 40 mechanically and electrically connects the glass resonator 30 and the annular electrode 22c. Thereafter, heat at 280 °C for 30 minutes or more to bake the paste 40. The electrode film formed on the surface of the glass resonator 30 and the outer peripheral electrode 22o are electrically connected via the paste 40 and the wiring 25 (see FIG. 1). Thereafter, electrically connect between the electrode pad 23 and the BR pad 24 and the electrode 102 of the package 100 with an Au wire 110.

[0040] Describe the vacuum hermetic sealing process in step S6 with reference to the schematic cross-sectional view of FIG. 2. First, form an upper electrode frame 123 having a rectangular frame shape on the lid 130. The upper electrode frame 123 has a shape corresponding to the lower electrode frame 121 of the frame body 103. Next, place the package 100 formed in the aforementioned mounting process in a vacuum. Install a seal ring 122 having the same frame shape as the lower electrode frame 121 on the lower electrode frame 121. Place the lid 130 on the seal ring 122. At this time, adjust the positions so that the lower electrode frame 121, the seal ring 122, and the upper electrode frame 123 overlap each other.

[0041] Thereafter, heat at 360 °C to perform a degassing process and vacuum hermetically seal the sensor element 10 by eutectic bonding. At this time, a load may be applied to the lid 130 and pressed as necessary. Since hermetic sealing can be performed by the seal portion 120, the internal pressure of the package 100 can be maintained at a desired degree of vacuum.

[0042] (Effect) The problem will be described. The back surface 21b of the glass substrate 21 is adhesively fixed to the mounting surface 101 of the package 100 by the die bonding material 50. Gas is discharged from this die bonding material 50. However, if the gas cannot be sufficiently discharged from the die bonding material 50, outgassing may occur from the die bonding material 50 after vacuum hermetic sealing (step S6). As a result, it may become difficult to achieve a high vacuum inside the package 100 or to maintain a high vacuum state. Therefore, in the technology of this specification, the gas released from the inside of the die bonding material 50 can be efficiently discharged to the outside of the die bonding material 50 by the groove 21t formed on the back surface 21b. Since the gas can be sufficiently discharged from the die bonding material 50, the outgassing can be completed before vacuum hermetic sealing. Since the outgassing generated from the die bonding material 50 after vacuum hermetic sealing can be suppressed, it becomes possible to achieve a high vacuum inside the package 100 and to maintain the high vacuum state.

[0043] As shown in FIG. 3, a part of the die bonding material 50 has entered from the opening of the groove 21t to the inner side of the groove 21t. And a space SP is formed. Thereby, the adhesive surface area between the die bonding material 50 and the back surface 21b can be increased by the amount of the die bonding material 50 that has entered the groove 21t. Also, the space SP can function as a gas discharge path. It becomes possible to achieve both strong adhesion and high-efficiency gas discharge.

[0044] As shown in FIGS. 4 and 5, the plurality of grooves 21t intersect the outer peripheral contour of the die bonding region DR. Thereby, a plurality of outlets of the gas discharge path can be formed along the outer peripheral contour of the die bonding region DR. Also, the plurality of grooves 21t intersect the outer periphery of the glass substrate 21. Thereby, a plurality of outlets of the gas discharge path can be formed along the side 21x of the glass substrate 21. Therefore, it becomes possible to efficiently exhaust the outgassing from the center side to the outside of the die bonding material 50.

[0045] The gas generated from the die bond material 50 is more likely to accumulate in the central portion of the application area of the die bond material 50 than in the peripheral portion. In this embodiment, as shown in FIG. 4, the density at which the grooves 21t are formed is higher in the central region R1 of the glass substrate 21 than in the outer peripheral region R2. As a result, it becomes possible to more efficiently exhaust the outgas that accumulates in the central region of the die bond material 50.

[0046] (Modification of Example 1) As shown in FIG. 3, in each of the plurality of grooves 21t, the depth D1 and the width W1 are defined. The depth D1 may be equal to or greater than the width W1. The groove 21t having such an aspect ratio can be formed by anisotropic dry etching. Thereby, even when the die bond material 50 enters the inside of the groove 21t, the cross-sectional area of the space SP can be sufficiently large and remain. It becomes possible to achieve both strong adhesion and high-efficiency gas discharge.

Example

[0047] In Example 2, various aspects of the die bond region DR will be described. Parts common to Example 1 and Example 2 are denoted by the same reference numerals, and the description thereof will be omitted. FIG. 12 shows the arrangement mode of the die bond region DR2 in Example 2. FIG. 12 is the same drawing as FIG. 5 of Example 1. Five die bond regions DR2 are formed in the glass substrate 21. The five die bond regions DR2 are arranged to be rotationally symmetric with respect to the central axis CA.

[0048] As described with reference to FIG. 4, the plurality of grooves 21t extend in the ±y direction. And the plurality of grooves 21t intersect the outer peripheral contour provided for each of the five die bond regions DR2. As a result, a plurality of outlets of the gas discharge path can be formed along the outer peripheral contours of the five die bond regions DR2. It becomes possible to exhaust the outgas that accumulates in the central portions of the five die bond regions DR2 from the outlets formed in the outer peripheral contours.

[0049] Note that since the plurality of grooves 21t only need to intersect the outer peripheral contours provided by each of the five die bond regions DR2, they do not necessarily need to reach the side 21x of the glass substrate 21.

[0050] (Modification of Example 2) The shapes, numbers, and arrangement modes of the plurality of die bond regions may vary. The shape of the die bond region is not limited to circular, and for example, it can be ring-shaped or lattice-shaped. Also, the number of die bond regions is not limited to five, and for example, it can be various numbers of dot-like regions such as nine points or sixteen points.

Example

[0051] In Example 3, various modes of the plurality of grooves 21t will be described. Parts common to Example 1 and Example 3 are denoted by the same reference numerals, and the description thereof will be omitted. FIGS. 13 and 14 show the modes of the grooves 21t in Example 3. FIGS. 13 and 14 are the same drawings as FIG. 4 of Example 1.

[0052] In the mode of FIG. 13, the plurality of grooves 21t extend parallel to the y-axis and also parallel to the x-axis. Thereby, a plurality of intersections can be formed by the plurality of grooves 21t that are orthogonal to each other.

[0053] In the mode of FIG. 14, the plurality of grooves 21t include a circular part 21tc and a radial part 21tr. The circular part 21tc is a circular groove centered on the central axis CA of the glass substrate 21. The radial part 21tr is a groove extending radially from the central axis CA in all directions.

[0054] Also in the modes of FIGS. 13 and 14, in the central region R1, the density of the plurality of grooves 21t formed is higher than that in the outer peripheral region R2. Thereby, it becomes possible to exhaust the outgas generated from the central region of the die bond material 50 more efficiently.

Example

[0055] In Example 4, an embodiment in which a plurality of grooves are formed in the mounting surface 101 of the package 100 will be described. Parts common to Example 1 and Example 4 are denoted by the same reference numerals, and the description thereof will be omitted. FIG. 15 shows a cross-sectional view of the sensor element 10 in Example 4. FIG. 15 is a drawing similar to FIG. 3 of Example 1. FIG. 16 shows a top view of the package 100 in Example 4. FIG. 16 is a drawing similar to FIG. 5 of Example 1. In FIG. 16, for clarity, the arrangement region R21 where the glass substrate 21 is arranged is indicated by a dotted line.

[0056] As shown in FIG. 16, a plurality of grooves 101t are formed in the mounting surface 101 of the package 100. The plurality of grooves 101t extend parallel to the y-axis. The length L1 in the y direction of the plurality of grooves 101t is larger than the length L2 in the y direction of the glass substrate 21. Also, the ends of the plurality of grooves 101t protrude in the ±y directions from the arrangement region R21 of the glass substrate 21. Note that the plurality of grooves 101t may communicate with each other.

[0057] As shown in FIG. 15, each of the plurality of grooves 101t has a depth D101 and a width W101. The depth D101 is equal to or greater than the width W101. The depth D101 is not particularly limited, and may be, for example, in the range of 2 to 50 μm. The plurality of grooves 101t can be formed by etching or laser ablation. Also, the back surface 21b of the glass substrate 21 is flat without grooves formed therein.

[0058] The die bonding material 50 has entered from the opening of the groove 101t to the inner side of the groove 101t. A space SP is formed by the void remaining between the entering die bonding material 50 and the bottom surface 101tm of the groove 101t.

[0059] The mounting process of the pedestal electrode in step S4 (FIG. 6) will be described. A die bonding material 50 is applied to the back surface 21b of the glass substrate 21 or the mounting surface 101 of the package 100. Then, the back surface 21b is pressed against the mounting surface 101. When pressed, the die bonding material 50 enters the inside of the groove 101t. A space SP is formed between the entered die bonding material 50 and the bottom surface 101tm of the groove 101t. Thereafter, the die bonding material 50 is hardened by heat treatment. The space SP is not blocked even by this heat treatment. Therefore, the space SP can function as an exhaust path for outgas generated from the die bonding material 50.

[0060] (Modification of Example 4) A plurality of grooves 101t may be formed on the mounting surface 101, and a plurality of grooves 21t may be formed on the back surface 21b of the glass substrate 21. The plurality of grooves 101t and the plurality of grooves 21t may have overlapping portions in a top view. Thereby, it becomes possible to form a larger cross-sectional area of the space SP in the overlapping portion.

[0061] As described above, specific examples of the present invention have been described in detail, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. Also, the technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Further, the technology illustrated in this specification or the drawings can achieve a plurality of purposes simultaneously, and has technical usefulness by achieving one of those purposes itself.

[0062] (Modification) The planar shape of the groove 21t or the groove 101t may be various. For example, the width of the groove may be changed continuously or stepwise. Also, the width of the groove may be made wider in the central region R1 than in the outer peripheral region R2. Thereby, it becomes possible to exhaust the outgas accumulated in the central region of the die bonding material 50 more efficiently. Also, grooves having a plurality of different widths may be combined.

[0063] The cross-sectional shape of the groove 21t may be various. For example, it may be a rectangular shape with a constant width from the opening to the bottom surface 21tm, a forward taper shape with the width narrowing from the opening to the bottom surface 21tm, a reverse taper shape with the width widening from the opening to the bottom surface 21tm, and the like. The groove 21t having such a cross-sectional shape can be formed by anisotropic dry etching. By making the cross-section a rectangular shape or a reverse taper shape, the cross-sectional area of the groove can be increased while maintaining the narrow width of the opening. Thereby, it becomes possible to achieve both an increase in the contact area between the back surface 21b and the mounting surface 101 and an increase in the space SP.

[0064] The aspects of the present technology are listed below. [Aspect 1] A package configured to be hermetically sealed by a lid portion, A glass substrate stored in the package, wherein the back surface is adhesively fixed to the mounting surface in the package, An electrode portion disposed on the surface of the glass substrate, A glass vibrator including a tubular column portion having a central axis and a hollow substantially hemispherical peripheral portion centered on the central axis, wherein the column portion is fixed to the electrode portion, Comprising, At least one of the back surface of the glass substrate and the mounting surface of the package has a groove formed therein, A die bond material is disposed between the back surface and the mounting surface, An inertial force sensor. [Aspect 2] The die bond material has penetrated from the opening of the groove to the inner side of the groove, An inertial force sensor according to Aspect 1, wherein a space is formed between the penetrated die bond material and the bottom surface of the groove. [Aspect 3] When viewed from a direction perpendicular to the glass substrate, a die bond region where the die bond material exists is formed within the glass substrate, The inertial force sensor according to aspect 1 or 2, wherein the groove intersects the outer peripheral contour of the die bond region. [Aspect 4] A plurality of the die bond regions are formed in the glass substrate, The inertial force sensor according to aspect 3, wherein the groove intersects the plurality of outer peripheral contours provided in each of the plurality of die bond regions. [Aspect 5] The inertial force sensor according to any one of aspects 1-4, wherein the groove intersects the outer periphery of the glass substrate when viewed from a direction perpendicular to the glass substrate. [Aspect 6] The inertial force sensor according to any one of aspects 1-5, wherein the depth of the groove is equal to or greater than the width of the groove. [Aspect 7] A plurality of the grooves are formed, The inertial force sensor according to any one of aspects 1-6, wherein the density at which the grooves are formed is higher in a region near the center of the glass substrate than in a region near the outer periphery of the glass substrate. [Aspect 8] When viewed from a direction perpendicular to the glass substrate, the glass substrate has a rectangular shape, The inertial force sensor according to any one of aspects 1-7, wherein the groove includes at least one of a portion parallel to a side of the glass substrate, a portion circular with respect to the center of the glass substrate, or a radial portion extending from the center of the glass substrate to the periphery. [Aspect 9] A package configured to be hermetically sealed by a lid, A glass substrate stored in the package, wherein the back surface of the glass substrate is adhesively fixed to a mounting surface in the package, An electrode portion disposed on the surface of the glass substrate, A glass vibrator including a tubular column portion having a central axis and a hollow substantially hemispherical peripheral portion centered on the central axis, wherein the column portion is fixed to the electrode portion, the glass vibrator, A method for manufacturing an inertial force sensor including: A step of forming a groove on at least one of the back surface of the glass substrate and the mounting surface of the package; A step of bringing the mounting surface into contact with the back surface after applying a die bonding material to the mounting surface of the package or the back surface of the glass substrate; A step of hermetically sealing the package with the lid; A method for manufacturing an inertial force sensor, comprising the steps above.

Explanation of Signs

[0065] 1: Gyro sensor 20: Pedestal electrode 21: Glass substrate 21t: Groove 22: Silicon substrate 22c: Annular electrode 30: Glass vibrator 30p: Column portion 30c: Peripheral portion 50: Die bonding material 100: Package 101: Mounting surface

Claims

1. A package configured to be hermetically sealed by a lid portion, A glass substrate stored in the package, wherein the back surface of the glass substrate is adhesively fixed to the mounting surface in the package, An electrode portion disposed on the surface of the glass substrate, A glass oscillator including a tubular column portion having a central axis and a hollow substantially hemispherical peripheral portion centered on the central axis, wherein the column portion is fixed to the electrode portion, Comprising, A groove is formed in at least one of the back surface of the glass substrate and the mounting surface of the package, A die bond material is disposed between the back surface and the mounting surface, An inertial force sensor.

2. The die bond material has penetrated from the opening of the groove to the inner side of the groove, The inertial force sensor according to claim 1, wherein a space is formed between the penetrated die bond material and the bottom surface of the groove.

3. When viewed from a direction perpendicular to the glass substrate, a die bond region where the die bond material exists is formed within the glass substrate, The inertial force sensor according to claim 1, wherein the groove intersects the outer peripheral contour of the die bond region.

4. A plurality of die bond regions are formed within the glass substrate, The inertial force sensor according to claim 3, wherein the groove intersects a plurality of the outer peripheral contours each provided by the plurality of die bond regions.

5. When viewed from a direction perpendicular to the glass substrate, the groove intersects the outer periphery of the glass substrate. The inertial force sensor according to claim 1.

6. The inertial force sensor according to claim 1, wherein the depth of the groove is greater than or equal to the width of the groove.

7. A plurality of the grooves are formed, and a density at which the grooves are formed is higher in a region near the center of the glass substrate than in a region near the outer periphery of the glass substrate. The inertial force sensor according to claim 1.

8. When viewed from a direction perpendicular to the glass substrate, the glass substrate has a rectangular shape, and the groove includes at least one of a portion parallel to a side of the glass substrate, a portion circular with respect to the center of the glass substrate, and a radial portion extending from the center of the glass substrate to the periphery. The inertial force sensor according to claim 7.

9. A package configured to be hermetically sealed by a lid portion, A glass substrate stored in the package, wherein a back surface of the glass substrate is adhesively fixed to a mounting surface in the package, An electrode portion disposed on a surface of the glass substrate, A glass vibrator including a column portion having a central axis and a hollow substantially hemispherical peripheral portion centered on the central axis, wherein the column portion is fixed to the electrode portion. The glass vibrator, and a method for manufacturing an inertial force sensor including: A step of forming a groove in at least one of the back surface of the glass substrate and the mounting surface of the package; A step of applying a die bond material to the mounting surface of the package or the back surface of the glass substrate and then bringing the mounting surface into contact with the back surface; A step of hermetically sealing the package with the lid portion; and a method for manufacturing an inertial force sensor including the steps.

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