Inertia force sensor and method of manufacturing inertia force sensor

Abstract

To provide an inertia force sensor comprising a package capable of suppressing generation of a leak path, and a method of manufacturing the same.SOLUTION: A gyro sensor 1 that is an inertia force sensor comprises: a package 100 including an opening frame 103a in a rectangular shape; a sensor section disposed inside of the package 100; a lid 130 covering the entire opening frame and including a plurality of corners, the lid being a metallic lid part having a tabular shape; and a junction frame 120 which is disposed along the opening frame, has a closed ring shape and joins the opening frame and the lid part. On a top face of the lid part, first and second projections P1 and P2 are formed in regions corresponding to the plurality of corners, and the first and second projections extend along the junction frame. The first projection is disposed radially outside of the ring shape with respect to the second projection. In a case where an electrode face 60e is brought into contact with the top face of the lid part, the electrode face is in contact only with the first and second projections.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present specification relates to an inertial force sensor and a method for manufacturing an inertial force sensor. [Background technology]

[0002] Patent Document 1 discloses an electronic component in which an electronic component element (such as an inertial force sensor) is housed in a ceramic package and sealed with a metal lid. Specifically, the electronic component element is housed in a housing-shaped ceramic package with one side open. A rectangular metal lid is placed around the opening of the ceramic package to cover the ceramic package. The metal lid and the ceramic package are then welded together. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-22013 Summary of the Invention [Problem to be solved by the invention]

[0004] During welding, large residual stresses are generated due to sudden temperature increases and decreases. Stress is particularly concentrated at the corners of the rectangular metal lid. This stress concentration can cause cracks to form in the welded joint. If the cracks expand, a leak path to the outside is created, making it difficult to maintain a high vacuum inside the package. [Means for solving the problem]

[0005] The inertial force sensor disclosed in this specification includes a package with a rectangular opening frame, a sensor unit disposed inside the package, a flat metal lid that covers the entire opening frame and has multiple corners, and a joining frame that is disposed along the opening frame and has a closed ring shape, joining the opening frame and the lid. First and second protrusions are formed on the top surface of the lid in areas corresponding to the multiple corners. The first and second protrusions extend along the joining frame. The first protrusions are disposed radially outward of the ring shape relative to the second protrusions. When an electrode surface is brought into contact with the top surface of the lid, the electrode surface is configured to be in contact only with the first and second protrusions.

[0006] During welding, the contact point between the top surface of the lid and the electrode surface generates heat, melting the joining frame and forming a weld. According to the above structure, first and second protrusions are arranged in areas corresponding to the corners. When the electrode surface is brought into contact with the top surface of the lid, the electrode surface is configured to contact only the first and second protrusions. This allows two heating points to be arranged along the radial direction of the ring shape. Therefore, the radial width of the weld can be increased compared to when a single heating point is used. By increasing the width of the weld, stress can be dispersed, making it possible to prevent cracks from occurring. This also makes it possible to suppress the formation of gas leak paths connecting the outside and the inside. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a top view of the gyro sensor 1. [Figure 2] FIG. 2 is a top view of the gyro sensor 1. [Figure 3] FIG. 2 is a cross-sectional view of the gyro sensor 1. [Figure 4] FIG. 2 is a cross-sectional view of the gyro sensor 1. [Figure 5] FIG. [Figure 6]FIG. 2 is a cross-sectional view illustrating seam welding. [Figure 7] FIG. 2 is a cross-sectional view illustrating seam welding. [Figure 8] 3 is a flowchart showing an outline of a manufacturing process for the gyro sensor 1. [Figure 9] 2A to 2C are schematic diagrams illustrating a manufacturing process of the gyro sensor 1. [Figure 10] FIG. 10 is a top view of the gyro sensor 1 according to the second embodiment. [Figure 11] FIG. 10 is a top view of the joint frame 120 in the second embodiment. [Figure 12] FIG. 10 is a cross-sectional view of the gyro sensor 1 according to the third embodiment. [Figure 13] FIG. 10 is a top view of the joint frame 120 in the third embodiment. [Figure 14] FIG. 10 is a top view of the gyro sensor 1 according to a modified example. DETAILED DESCRIPTION OF THE INVENTION [Example]

[0008] FIG. 1 shows a top view of a gyro sensor 1 according to this embodiment. For clarity, FIG. 1 shows a state in which the lid 130 has been removed. FIG. 2 shows a top view of the gyro sensor 1 including the lid 130. In FIG. 2, the joint frame 120, which is hidden underneath, is indicated by a dotted line. FIG. 3 shows a cross-sectional view taken along line III-III in FIGS. 1 and 2. FIG. 3 is a cross-sectional view taken along the xz plane passing through the central axis CA. That is, FIG. 3 is a cross-sectional view that does not pass through a first protrusion P1 and a second protrusion P2, which will be described later. FIG. 4 shows a cross-sectional view taken along line IV-IV. FIG. 4 is a cross-sectional view taken along the xz plane passing through a corner region CR, which will be described later. That is, FIG. 4 is a cross-sectional view that passes through the first protrusion P1 and the second protrusion P2.

[0009] The gyro sensor 1 mainly includes a sensor element 10, a package 100, and a lid 130. The sensor element 10 is vacuum-tightly sealed in the package 100.

[0010] (Configuration of sensor element 10) The sensor element 10 mainly comprises a base electrode 20, a glass oscillator 30, and paste 40. The base electrode 20 has a structure in which a silicon substrate 22 is laminated on a glass substrate 21.

[0011] The glass substrate 21 is made of a glass material that can be anodically bonded to the silicon substrate 22. An annular ring groove 21r is formed on the surface 21f of the glass substrate 21. A rim portion 30r of the glass vibrator 30 is inserted into the ring groove 21r.

[0012] The silicon substrate 22 includes a ring electrode 22c, multiple segmented electrodes 22d, and an outer peripheral electrode 22o. The ring electrode 22c is disposed on the surface 21f of the glass substrate 21. The ring electrode 22c has a cylindrical shape about a central axis CA and includes a through-hole 22h. The central axis CA passes through the center of the glass substrate 21 and is perpendicular to the surface 21f. The multiple segmented electrodes 22d are disposed rotationally symmetrically on a circle centered on the central axis CA. The multiple segmented electrodes 22d surround the ring electrode 22c. An electrode pad 23 is formed on each of the multiple segmented electrodes 22d. An annular ring-shaped through-hole 22r is formed between the outer periphery of the ring electrode 22c and the inner periphery of the multiple segmented electrodes 22d. A rim portion 30r of the glass vibrator 30 is inserted into the ring-shaped through-hole 22r. The outer peripheral electrode 22o surrounds the periphery of the segmented electrode 22d. The peripheral electrode 22o is connected to the annular electrode 22c by four wires 25. In this embodiment, the wires 25 are made of an Al film. BR pads 24 are disposed at the four corners of the peripheral electrode 22o.

[0013] The glass vibrator 30 includes a pillar portion 30p and a peripheral portion 30c. The pillar portion 30p is a tubular portion having a central axis CA. The peripheral portion 30c is a hollow, approximately hemispherical portion centered on the central axis CA. The cross-sectional shape of the glass vibrator 30 in a plane passing through the central axis CA is approximately M-shaped. The material of the glass vibrator 30 is fused silica (quartz).

[0014] A conductive film (not shown) is formed on the surface of the glass vibrator 30. Various materials can be used for the conductive film. In this example, the conductive film was a TiN film.

[0015] The glass vibrator 30 is fixed to 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. Specifically, the bottom of the column portion 30p is adhered to the annular electrode 22c by 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 below. The paste 40 electrically connects the conductive film on the surface of the glass vibrator 30 to the annular electrode 22c. The annular electrode 22c is connected to the BR pad 24 via the wiring 25 and the peripheral electrode 22o. Therefore, the conductive film on the surface of the glass vibrator 30 and the BR pad 24 are electrically connected.

[0016] A die bond material 50 is disposed between the rear 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 bond and fix the glass substrate 21 to the mounting surface 101. 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 into an organic binder material.

[0017] (Gyro sensor 1 operation) A capacitor is formed between each of the multiple split electrodes 22d and the glass vibrator 30. An electrical signal is applied to the multiple split electrodes 22d from an external control circuit (not shown) via the multiple pads 102p. By generating an electrostatic attraction between the glass vibrator 30 and the multiple split electrodes 22d, the glass vibrator 30 is excited in wine-glass mode at the resonant frequency. When an angular velocity ωz is applied around the z-axis in this state, a Coriolis force is generated. An amplitude corresponding to the generated Coriolis force is then generated in the detection direction. The generated amplitude can be detected by a change in capacitance of a capacitor formed between the split electrode 22d and the glass vibrator 30. As described above, gyro sensor 1, which is an inertial force sensor, functions.

[0018] (Package 100 configuration) The configuration of the package 100 will be described with reference to FIGS. 1 and 3. A metal mounting surface 101 is disposed on the bottom surface inside the package 100. A plurality of electrodes 102 are disposed 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 wires 110. In this embodiment, the wires 110 are Au wires. As shown in FIG. 3, a plurality of pads 102p are disposed outside the package 100. The plurality of pads 102p correspond to the plurality of electrodes 102 and are connected to 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.

[0019] A rectangular frame 103 is disposed around the outer periphery of the multiple electrodes 102. The frame 103 may be made of any insulating material (e.g., ceramic). An opening frame 103a is formed on the upper surface of the frame 103. As shown in FIG. 1, the opening frame 103a has a rectangular shape. The opening frame 103a also has four corners 103c.

[0020] A joining frame 120 is disposed on the upper surface of the frame body 103. The joining frame 120 has a closed ring shape. The joining frame 120 is disposed along the opening frame 103a. Before the gyro sensor 1 is assembled, the joining frame 120 is a separate component from the opening frame 103a. The joining frame 120 is joined to the opening frame 103a and the lid 130 by a welding process, which will be described later. The joining frame 120 may be made of various materials. For example, metals such as kovar, nickel, and 42 alloy can be used as the material for the joining frame 120. The thickness of the joining frame 120 can be adjusted as appropriate. Specific details of the joining frame 120 will be described later.

[0021] (Lid 130 configuration) The lid 130 is a metal cover. The lid 130 has a flat plate shape. The lid 130 covers the entire opening frame 103a. The lid 130 may be made of various materials. For example, the lid 130 may be made of metals such as kovar, nickel, and 42 alloy. The lid 130 may also be made of a metal with a higher melting point than the joining frame 120. The thickness of the lid 130 can be adjusted as appropriate.

[0022] 2, the lid 130 has four corners 130c. Corner regions CR are defined on the top surface 130u of the lid 130 in correspondence with each of the four corners 130c. The corner regions CR are regions where stress concentration due to seam welding particularly occurs. The extent of the corner regions CR can be determined appropriately depending on the conditions for seam welding and the structure of the package 100.

[0023] A groove TR is formed in the corner region CR so as to cut out the outer periphery of the upper surface 130u. This forms a first protrusion P1 and a second protrusion P2, as shown in FIG. 4. The apex P1t of the first protrusion P1 is located lower than the apex P2t of the second protrusion. That is, the first protrusion P1 and the second protrusion P2 form a two-step staircase shape.

[0024] As shown in Figure 2, the first protrusion P1 and the second protrusion P2 are located within the arrangement range of the joining frame 120. The first protrusion P1 and the second protrusion P2 extend along the joining frame 120. Here, a center point CP of the ring-shaped joining frame 120 is defined. The direction toward the center point CP is defined as the radial direction of the joining frame 120. The first protrusion P1 is located radially outward of the second protrusion P2.

[0025] 4, the joint frame 120 has an outer circumferential contour line 120o. The first protrusion P1 is located radially inward from the outer circumferential contour line 120o by a distance D1.

[0026] (Configuration of joint frame 120) Fig. 5 shows a top view of the joint frame 120. Fig. 5 is a view seen from a direction perpendicular to the lid 130 (i.e., the z direction). For ease of understanding, Fig. 5 shows only the joint frame 120.

[0027] The joint frame 120 has a first section SE1 and a second section SE2. The first section SE1 is a section that includes the corner region CR. A first protrusion P1 and a second protrusion P2 are arranged within the first section SE1. The second section SE2 is a section that is arranged between adjacent first sections SE1. In other words, the second section SE2 is arranged on the four sides that connect the corner 103c. The first protrusion P1 and the second protrusion P2 are not arranged within the second section SE2.

[0028] A first weld WE1 is formed in the first section SE1. A second weld WE2 is formed in the second section SE2. In FIGS. 3, 4, and 5, the first weld WE1 and the second weld WE2 are shown filled in gray. The first weld WE1 and the second weld WE2 are regions to which a temperature exceeding the melting temperature of the joint frame 120 is applied during the seam welding process. The opening frame 103a and the lid 130 are joined to each other by the first weld WE1 and the second weld WE2. This allows the interior of the package 100 to be hermetically sealed.

[0029] The first weld zone WE1 has a first weld width W1 in the short direction of the joint frame 120. The second weld zone WE2 has a second weld width W2 in the short direction of the joint frame 120. The first weld width W1 is wider than the second weld width W2.

[0030] (Seam welding details) Seam welding will be described in detail using Figures 6 and 7. Figure 6 is a cross-sectional view of the same location as Figure 3, but without the first protrusion P1 and the second protrusion P2. Figure 7 is a cross-sectional view of the same location as Figure 4, but with the first protrusion P1 and the second protrusion P2. Figures 6 and 7 show a state in which the electrode surfaces 60e of a pair of roller electrodes 60 are in contact with the upper surface 130u of the lid 130. The electrode surfaces 60e are formed of conical surfaces.

[0031] As shown in FIG. 7, a plane PL is defined that includes the apex P1t of the first protrusion P1 and the apex P2t of the second protrusion P2. The plane PL forms a first angle A1 with respect to the upper surface 130u of the lid 130. The electrode surface 60e forms a second angle A2 with respect to the upper surface 130u of the lid 130. The first angle A1 and the second angle A2 are substantially the same. This allows the electrode surface 60e to come into point contact with only two points on the first protrusion P1 and the second protrusion P2.

[0032] On the other hand, as shown in Figure 6, in the area where the first protrusion P1 and the second protrusion P2 are not formed, the electrode surface 60e is configured to be able to make point contact with only one point on the outer peripheral edge 130p of the lid 130.

[0033] The following describes the mode of seam welding. In seam welding, each of a pair of roller electrodes 60 is brought into point contact with a corner surrounding the outer periphery of the upper surface 130u of the lid 130. Then, an AC current is passed between the pair of roller electrodes 60 via the lid 130. Since the electrode surface 60e of the roller electrode 60 and the lid 130 are in point contact, heat is generated at the point contact due to high electrical resistance. In other words, if the resistance at the point contact is R and the current flowing therethrough is I, then I 2 The power indicated by R is consumed at this point contact location, becoming thermal energy and causing local heating. The point contact location reaches the highest temperature and is then transferred to the joining frame 120. A portion of the joining frame 120 located within a predetermined range from the point contact location is heated to above its melting temperature and melts. The melted portion becomes the welded portion described above, thereby seam welding the lid 130 and the opening frame 103a together.

[0034] 6, in the region where the first protrusion P1 and the second protrusion P2 are not formed, there is only one point of contact at the outer peripheral edge 130p. Therefore, because there is only one heat source, heat is transferred only to a relatively narrow area (see arrow Y2). As a result, a second weld WE2 having a relatively narrow second weld width W2 is formed.

[0035] 7, in the region where the first protrusion P1 and the second protrusion P2 are formed, there are two point contacts: the first protrusion P1 and the second protrusion P2. Therefore, two heat generating points can be generated with a gap between them in the width direction of the joining frame 120, allowing heat to be transferred over a wider area (see arrow Y1). This allows the width of the region in the joining frame 120 that reaches the melting temperature to be expanded. As a result, a first weld WE1 can be formed that has a first weld width W1 that is wider than the second weld width W2.

[0036] The apexes P1t and P2t may be deformed and crushed by welding with the roller electrode 60. However, even in this case, the first protrusion P1 and the second protrusion P2 themselves remain. That is, the two-step staircase shape shown in FIG. 7 is maintained even after welding.

[0037] (Manufacturing method of gyro sensor 1) FIG. 8 shows a flowchart outlining the manufacturing process of the gyro sensor 1. In step S1, the sensor element 10 is fixed to the mounting surface 101 of the package 100 using a die bond material 50. A wire 110 is also wire-bonded. Note that various elements (e.g., IC chips) other than the sensor element 10 can also be stored inside the package 100. This completes the structure shown in the lower part of FIG. 9.

[0038] In step S2, the joining frame 120 is placed. At this stage, the joining frame 120 is a separate component from the package 100 and has a metal frame structure. The joining frame 120 of this frame is accurately placed in a predetermined position on the opening frame 103a (see arrow Y11 in FIG. 9). In step S3, the lid 130 is placed on the joining frame 120 (see arrow Y12 in FIG. 9).

[0039] The welding process is carried out in steps S4 to S6. Each step will be described below. In step S4, temporary welding is carried out. Specifically, two opposing sides are selected from the four sides of the opening frame 103a. Then, spot welding is performed near the midpoint of each of the two opposing sides.

[0040] In step S5, the two opposing sides are seam-welded. Specifically, the roller electrode 60 is moved over the two opposing sides at a constant speed while being heated by electrical current. At this time, in the corner regions CR, welding is performed by simultaneously contacting the electrode surface 60e with the first protrusion P1 and the second protrusion P2 (see FIG. 7). Thus, a first welded joint WE1 is formed. In addition, in the sides connecting adjacent corner regions CR, welding is performed by contacting the electrode surface 60e with the outer circumferential edge 130p (see FIG. 6). Thus, a second welded joint WE2 is formed.

[0041] In step S6, vacuum sealing is performed. Specifically, the gyro sensor 1 with two opposing sides welded is placed in a vacuum chamber. Then, while the chamber is evacuated, the remaining two unwelded sides are seam-welded. As a result, the joining frame 120, which was a separate component, is integrated with the lid 130 and the opening frame 103a. Because the joining frame 120 provides an airtight seal, the internal pressure of the package 100 can be maintained at a desired vacuum level.

[0042] (effect) The following describes the problem. Seam welding generates large residual stress due to rapid temperature increases and decreases. Stress is particularly concentrated at the corners of the rectangular lid 130. This stress concentration can cause cracks in the joining frame 120. If the cracks expand, a leak path to the outside is created, making it difficult to maintain a high vacuum inside the package 100. Therefore, the technology described in this specification provides a first protrusion P1 and a second protrusion P2 in the corner region CR. When the roller electrode 60 is brought into contact with the upper surface 130u of the lid 130, the electrode surface 60e is configured to contact only the first protrusion P1 and the second protrusion P2. This allows two heating points to be arranged along the radial direction, as described in Figure 7. Therefore, the width of the weld can be increased compared to a weld formed using a single heating point as shown in Figure 6. That is, the first weld width W1 (FIG. 7) of the first weld WE1 that welds the corner can be made larger than the second weld width W2 (FIG. 6) of the second weld WE2 that welds the side. By increasing the width of the corner weld, stress at the corner can be dispersed, making it possible to prevent cracks from occurring. Since the formation of a gas leak path connecting the outside and the inside can be suppressed, it becomes possible to maintain a high vacuum state inside the package 100.

[0043] In the technology of this specification, the first protrusion P1, which serves as a heat generation point, is positioned radially inward from the outer peripheral contour 120o of the joint frame 120 by a distance D1 (see FIG. 4). This allows the first weld WE1 to be formed by thermal conduction even in an area of ​​the joint frame 120 that is positioned radially outward from the first protrusion P1. This makes it possible to increase the first weld width W1 compared to when the first protrusion P1 and the outer peripheral contour 120o are in the same radial position (i.e., when the outer peripheral contour 120o is positioned vertically below the first protrusion P1). [Example]

[0044] In Example 2, an embodiment in which the corners of the first protrusion P1 and the second protrusion P2 are rounded will be described. Portions common to Examples 1 and 2 are designated by the same reference numerals, and descriptions thereof will be omitted. FIG. 10 shows a top view of the gyro sensor 1 equipped with a lid 130 of Example 2. In FIG. 10, the joint frame 120 hidden underneath is indicated by a dotted line. FIG. 11 also shows a top view of the joint frame 120. For ease of understanding, FIG. 11 shows only the joint frame 120.

[0045] As shown in Fig. 10, the four corners 130c of the lid 130 have rounded corners. The grooves TR formed within the corner regions CR also have rounded corners. The first protrusion P1 and the second protrusion P2 each have a curved region CU that curves in an arc shape along the corners 130c. As a result, as shown in Fig. 11, the first weld WE1 formed along the first protrusion P1 and the second protrusion P2 also has a curved region CW.

[0046] (effect) If the first welded portion WE1 has a corner, stress may concentrate at the corner. Therefore, in the technology of Example 2, the first protrusion P1 and the second protrusion P2 have a curved region CU, so that the first welded portion WE1 can be formed to have a curved region CW. This makes it possible to realize a structure in which the first welded portion WE1 does not have a corner. Since the stress concentration at the first welded portion WE1 can be further dispersed, it becomes possible to prevent cracks from occurring. [Example]

[0047] In Example 3, an embodiment in which a void VD is formed in the first welded portion WE1 will be described. Portions common to Examples 1 and 3 are designated by the same reference numerals, and descriptions thereof will be omitted. FIG. 12 shows a cross-sectional view of Example 3. FIG. 12 is a cross-sectional view similar to FIG. 4, showing a cross section perpendicular to the extension direction (y direction) of the joint frame 120. FIG. 13 shows a top view of the joint frame 120. For ease of understanding, FIG. 13 shows only the joint frame 120. The void VD is also indicated by a dotted line.

[0048] 12, a gap VD is formed in the first welded portion WE1 of the joint frame 120. The cross-sectional shape of the gap VD is approximately circular. The gap VD is located in the region between the first protrusion P1 and the second protrusion P2 in the radial direction (x direction).

[0049] As shown in FIG. 13, in the first section SE1, a gap VD is formed in the first welded portion WE1 of the joint frame 120 so as to extend in the circumferential direction.

[0050] (Method for forming the gap VD) In welding, when there is a temperature difference in the molten metal, the molten metal tends to move toward the higher temperature side. In the technology of Example 3, the distance L1 in the x direction between the first protrusion P1 and the second protrusion P2 is set to a certain value or greater. This allows the two heat sources to be appropriately spaced apart. Therefore, during welding, a temperature distribution is formed in the molten metal formed on the joining frame 120, in which the temperature at the intermediate position is lower than the temperatures at the positions directly below the first protrusion P1 and the second protrusion P2. This allows the molten metal to move from the intermediate position toward both sides of the intermediate position (the positions directly below the first protrusion P1 and the second protrusion P2). As a result, a gap VD is formed at the intermediate position. Furthermore, the cross-sectional shape of the gap VD can be formed into a substantially circular shape due to the surface tension of the molten metal. By moving the roller electrode 60 in the circumferential direction, the gap VD can be formed to extend in the circumferential direction.

[0051] (effect) A void VD is formed in the first welded portion WE1. This allows the first welded portion WE1 to have a double ring shape including an inner welded portion WE1i and an outer welded portion WE1o. Even if a crack occurs in one of the inner welded portion WE1i and the outer welded portion WE1o due to stress concentration at the corner, the void VD can prevent the crack from propagating to the other side of the inner welded portion WE1i or the outer welded portion WE1o. Since the crack can be prevented from communicating with the outside, the creation of a leak path can be suppressed. It is possible to maintain a high vacuum state inside the package 100.

[0052] The cross-sectional shape of the gap VD is made substantially circular, which makes it possible to reduce stress concentration in the gap VD.

[0053] Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. Furthermore, the technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings can achieve multiple objectives simultaneously, and achieving one of these objectives itself has technical utility.

[0054] (First Modification) On the upper surface 130u of the lid 130, the regions where the first protrusions P1 and the second protrusions P2 are formed are not limited to the corner regions CR. For example, as shown in FIG. 14, the first protrusions P1 and the second protrusions P2 may be formed in four side regions SR located between the four corner regions CR. In other words, the first protrusions P1 and the second protrusions P2 may be formed as a continuous unit so as to surround the outer periphery of the lid 130. This allows the width of the welded portion to be the first welded portion WE1 around the entire periphery of the opening frame 103a. Because the weld width in the four side regions SR can be widened, the formation of leak paths on the four sides can be suppressed. This makes it possible to further improve airtightness.

[0055] (Second Modification) In this embodiment, the radial width of the joint frame 120 is constant, but this is not limited to this. The width of the joint frame 120 in the first section SE1 (the section including the corner region CR) may be larger than the width of the joint frame 120 in the second section SE2 (the section located between adjacent first sections SE1). As a specific example, the shape of the joint frame 120 may be the shape of the first welded portion WE1 and the second welded portion WE2 in FIG. 5. This also makes it possible to realize a structure in which the first weld width W1 is larger than the second weld width W2, thereby dispersing stress at the corners.

[0056] (Third Modification) In steps S5 and S6 (FIG. 8), the seam welding using the first protrusion P1 and the second protrusion P2 may be performed in various ways. For example, the electrode surface 60e of the roller electrode 60 may be brought into contact with the first protrusion P1 to perform a first welding, and then the electrode surface 60e may be brought into contact with the second protrusion P2 to perform a second welding. That is, the same location may be seam welded twice. When the electrode surface 60e is brought into contact with both the first protrusion P1 and the second protrusion P2 simultaneously to pass current, a difference in resistance between the two contact points may result in a difference in the amount of heat generated. On the other hand, when the process of bringing the electrode surface 60e into contact with the first protrusion P1 to pass current and the process of bringing the electrode surface 60e into contact with the second protrusion P2 to pass current are performed separately, there is no difference in resistance because there is only one contact point, and therefore no difference in the amount of heat generated. This makes it possible to suppress variations in the quality of seam welding.

[0057] (Fourth Modification) In this embodiment, the first protrusion P1 and the second protrusion P2 form a two-step staircase shape, but this is not limiting. A three-step or more staircase shape may be formed by providing three or more protrusions. The more protrusions there are, the more effective it is at suppressing the creation of leak paths, making it possible to achieve a stronger vacuum seal.

[0058] Aspects of the present technology are listed below. [Aspect 1] a package having a rectangular opening frame; a sensor unit disposed inside the package; a metal lid portion having a flat plate shape, the lid portion covering the entire opening frame and having a plurality of corners; a joining frame disposed along the opening frame, having a closed ring shape, and joining the opening frame and the lid portion; An inertial force sensor comprising: a first protrusion and a second protrusion are formed on the upper surface of the lid in areas corresponding to the plurality of corners, the first protrusion and the second protrusion extend along the joint frame, the first protrusion is disposed radially outward of the ring shape relative to the second protrusion, When the electrode surface is brought into contact with the upper surface of the lid portion, the electrode surface is configured to be able to come into contact with only the first protrusion and the second protrusion. Inertial force sensor. [Aspect 2] 2. The inertial force sensor according to aspect 1, wherein a top of the first protrusion is positioned lower than a top of the second protrusion. [Aspect 3] 3. The inertial force sensor according to claim 1, wherein, when viewed from a position vertically above the top surface of the lid, the first protrusion and the second protrusion include curved regions that are curved in an arc shape along the corners. [Aspect 4] the joint frame includes first sections corresponding to each of the plurality of corners and second sections disposed between adjacent first sections, The inertial force sensor according to any one of aspects 1 to 3, wherein the radial width of the joint frame in the first section is greater than the radial width of the joint frame in the second section. [Aspect 5] The joint frame includes first sections corresponding to each of the plurality of corners, In the first section, a gap extending in a circumferential direction of the ring shape is formed in the joining frame, The inertial force sensor according to any one of Aspects 1 to 4, wherein the gap is located in a region between the first protrusion and the second protrusion in the radial direction. [Aspect 6] 6. The inertial force sensor according to aspect 5, wherein the gap has a substantially circular cross-sectional shape in a cross section perpendicular to the extension direction of the joint frame. [Aspect 7] On the top surface of the lid, four sides are located between the four corners, The inertial force sensor according to any one of aspects 1 to 6, wherein the first protrusions and the second protrusions are formed on the four sides. [Aspect 8] The inertial force sensor according to any one of aspects 1 to 7, wherein the first protrusion is located inside an outer contour line of the opening frame when viewed from a position vertically above the top surface of the lid. [Aspect 9] a package having a rectangular opening frame; a sensor unit disposed inside the package; a metal lid portion having a flat plate shape, the lid portion covering the entire opening frame and having a plurality of corners; a joining frame disposed along the opening frame, having a closed ring shape, and joining the opening frame and the lid portion; A method for manufacturing an inertial force sensor comprising: a first protrusion and a second protrusion are formed on the upper surface of the lid in areas corresponding to the plurality of corners, the first protrusion and the second protrusion extend along the joint frame, the first protrusion is disposed radially outward of the ring shape relative to the second protrusion, when an electrode surface of the roller electrode is brought into contact with the upper surface of the lid portion, the electrode surface is configured to be able to come into contact with only the first protrusion and the second protrusion, The method for manufacturing the inertial force sensor includes: fixing the sensor unit inside the package; placing the joint frame on the opening frame; placing the lid portion on the joining frame; a welding step of seam-welding the opening frame and the lid portion together using the roller electrode in a vacuum atmosphere; It is equipped with In the welding step, welding is performed by simultaneously bringing the electrode surface into contact with the first protrusion and the second protrusion, or by bringing the electrode surface into contact with the first protrusion to perform a first welding, and then bringing the electrode surface into contact with the second protrusion to perform a second welding. A method for manufacturing an inertial force sensor. [Aspect 10] a plane including a top of the first protrusion and a top of the second protrusion has a first angle with respect to an upper surface of the lid; the electrode surface has a second angle with respect to the top surface of the lid; 10. The method for manufacturing an inertial force sensor according to aspect 9, wherein the first angle and the second angle are substantially equal to each other. [Explanation of symbols]

[0059] 1: Gyro sensor 10: Sensor element 60: Roller electrode 60e: Electrode surface 103a: Opening frame 103c: Corner 100: Package 120: Joint frame 130: Lid 130u: Upper surface CR: Corner region P1: First protrusion P2: Second protrusion P1t, P2t: Top

Claims

1. a package having a rectangular opening frame; a sensor unit disposed inside the package; a metal lid portion having a flat plate shape, the lid portion covering the entire opening frame and having a plurality of corners; a joining frame disposed along the opening frame, having a closed ring shape, and joining the opening frame and the lid portion; An inertial force sensor comprising: a first protrusion and a second protrusion are formed on the upper surface of the lid in areas corresponding to the plurality of corners, the first protrusion and the second protrusion extend along the joint frame, the first protrusion is disposed radially outward of the ring shape relative to the second protrusion, When an electrode surface is brought into contact with an upper surface of the lid portion, the electrode surface is configured to be able to come into contact with only the first protrusion and the second protrusion. Inertial force sensor.

2. The inertial force sensor according to claim 1 , wherein a top of the first protrusion is located below a top of the second protrusion.

3. 3. The inertial force sensor according to claim 2, wherein when viewed from a position vertically above the upper surface of the lid, the first protrusion and the second protrusion include curved regions that are curved in an arc shape along the corners.

4. the joint frame includes first sections corresponding to the plurality of corners, and second sections disposed between adjacent first sections, 4. The inertial force sensor according to claim 1, wherein the radial width of the joint frame in the first section is greater than the radial width of the joint frame in the second section.

5. The joint frame includes first sections corresponding to the plurality of corners, In the first section, a gap extending in a circumferential direction of the ring shape is formed in the joining frame, The inertial force sensor according to claim 1 , wherein the gap is located in a region between the first protrusion and the second protrusion in the radial direction.

6. The inertial force sensor according to claim 5 , wherein a cross-sectional shape of the gap in a cross section perpendicular to an extension direction of the joint frame is substantially circular.

7. On the top surface of the lid portion, four sides are located between the four corners, The inertial force sensor according to claim 1 , wherein the first protrusions and the second protrusions are formed on the four sides.

8. 2 . The inertial force sensor according to claim 1 , wherein the first protrusion is located inside an outer contour line of the opening frame when viewed from a position vertically above the top surface of the lid.

9. a package having a rectangular opening frame; a sensor unit disposed inside the package; a metal lid portion having a flat plate shape, the lid portion covering the entire opening frame and having a plurality of corners; a joining frame disposed along the opening frame, having a closed ring shape, and joining the opening frame and the lid portion; A method for manufacturing an inertial force sensor comprising: a first protrusion and a second protrusion are formed on the upper surface of the lid in areas corresponding to the plurality of corners, the first protrusion and the second protrusion extend along the joint frame, the first protrusion is disposed radially outward of the ring shape relative to the second protrusion, when an electrode surface of the roller electrode is brought into contact with the upper surface of the lid portion, the electrode surface is configured to be able to come into contact with only the first protrusion and the second protrusion, The method for manufacturing the inertial force sensor includes: fixing the sensor unit inside the package; placing the joint frame on the opening frame; placing the lid portion on the joining frame; a welding step of seam-welding the opening frame and the lid portion together using the roller electrode in a vacuum atmosphere; It is equipped with In the welding step, welding is performed by simultaneously bringing the electrode surface into contact with the first protrusion and the second protrusion, or by bringing the electrode surface into contact with the first protrusion to perform a first welding, and then bringing the electrode surface into contact with the second protrusion to perform a second welding. A method for manufacturing an inertial force sensor.

10. a plane including a top of the first protrusion and a top of the second protrusion has a first angle with respect to an upper surface of the lid; the electrode surface has a second angle with respect to the top surface of the lid; The method for manufacturing an inertial force sensor according to claim 9 , wherein the first angle and the second angle are substantially equal to each other.

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