Physical quantity sensor, physical quantity sensor device, and method for manufacturing the same

Abstract

Disclosed is a physical quantity sensor excellent in temperature characteristics and aging characteristics, a physical quantity sensor device, and a manufacturing method thereof. The physical quantity sensor (10) includes: a base portion (20); first, second, and third arm portions (31, 32, 33) connected to the base portion (20) and each provided with a fixed portion (80); a movable portion (40) disposed between the first and second arm portions (31, 32) and between the first and third arm portions (31, 33) when viewed in plan; a narrowed portion (50) disposed between the base portion (20) and the movable portion (40) and connecting the base portion (20) and the movable portion (40); and a physical quantity detection element (60) disposed across the narrowed portion (50) when viewed in plan and mounted to the base portion (20) and the movable portion (40), and a thin-walled portion (85, 86) is formed in at least one of the second and third arm portions (32, 33) at at least two sites.

Description

TECHNICAL FIELD

[0001] The present application relates to a physical quantity sensor, a physical quantity sensor device, and a manufacturing method of a physical quantity sensor device. BACKGROUND

[0002] For example, Patent Literature 1 discloses a physical quantity sensor in which, in a physical quantity sensor having a base portion, three arm portions, a movable portion, a narrowed portion, and a physical quantity detection element, fixed regions provided in the three arm portions are disposed in a first region and a second region divided by a first straight line passing through the center of the physical quantity detection element in a direction across the narrowed portion in plan view, and at least one of a third region of the first region on a base portion side than a second straight line and a fourth region of the second region on the base portion side than the second straight line in plan view, the second straight line passing through the narrowed portion and orthogonal to the first straight line.

[0003] Patent Literature 1: Japanese Patent Application Publication No. 2019-158475

[0004] However, the physical quantity sensor described in Patent Literature 1 has a problem in that, in a case where the fixed regions are fixed to a package or the like by an adhesive or the like, stress at the time of fixation, external force applied to the package, stress accompanying a difference in thermal expansion, or the like is transmitted to the physical quantity detection element via the fixed regions, and temperature characteristics and aging characteristics of the physical quantity sensor are deteriorated. SUMMARY

[0005] The physical quantity sensor includes a base portion, first, second, and third arm portions connected to the base portion and each provided with a fixed portion, a movable portion disposed between the first and second arm portions and between the first and third arm portions in plan view, a narrowed portion disposed between the base portion and the movable portion and connecting the base portion and the movable portion, and a physical quantity detection element disposed across the narrowed portion in the plan view and mounted to the base portion and the movable portion, and a thin-walled portion is formed in at least one of the second and third arm portions at at least two sites.

[0006] The physical quantity sensor device includes a physical quantity sensor having the above-described fixed portion, and a base portion to which the physical quantity sensor is fitted, and the fixed portion is mounted to the base portion.

[0007] The manufacturing method of the physical quantity sensor device includes the following steps: a step of preparing a physical quantity detecting element; a step of preparing a cantilever provided with a base portion, a first fixing portion, a second fixing portion, and a third fixing portion; a step of joining the physical quantity detecting element with the cantilever; a step of mounting the first fixing portion, the second fixing portion, and the third fixing portion to a base; and a step of separating the second fixing portion from the base portion or the third fixing portion from the base portion. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a perspective view showing a simple structure of a physical quantity sensor of a first embodiment.

[0009] Figure 2 is a plan view showing a simple structure of a cantilever provided in a physical quantity sensor of the first embodiment.

[0010] Figure 3 is a diagram showing a difference in stress on an element due to the presence or absence of a thin wall portion.

[0011] Figure 4 is a plan view showing a simple structure of a cantilever provided in a physical quantity sensor of a second embodiment.

[0012] Figure 5 is a plan view showing a simple structure of a cantilever provided in a physical quantity sensor of a third embodiment.

[0013] Figure 6 is a plan view showing a simple structure of a physical quantity sensor device of a fourth embodiment.

[0014] Figure 7 is a flowchart showing a manufacturing method of a physical quantity sensor device.

[0015] Figure 8 is a plan view showing a simple structure of a cantilever provided in a physical quantity sensor device of a fifth embodiment.

[0016] Figure 9 is a flowchart showing a manufacturing method of a physical quantity sensor device.

[0017] Figure 10 is a plan view showing a simple structure of a cantilever provided in a physical quantity sensor device of a sixth embodiment.

[0018] Figure 11 is an exploded assembly perspective view of a physical quantity sensor device of a seventh embodiment.

[0019] BRIEF DESCRIPTION OF DRAWINGS:

[0020] 10, 10a, 10b, 10c, 10d: physical quantity sensor; 15: cantilever; 20: base; 30: arm portion; 31: first arm portion; 32: second arm portion; 33: third arm portion; 40: movable portion; 50: narrowed portion; 60: physical quantity detection element; 61: joining member; 62: bonding wire; 70: mass portion; 71, 72: end portion; 74: joining member; 80: fixed portion; 81: first fixed portion; 82: second fixed portion; 83: third fixed portion; 85: thin-walled portion; 86: thin-walled portion; 100, 100a, 100b: physical quantity sensor device; 110: base; 110A: bottom wall; 110A1: inner surface; 110A2: outer surface; 110B: side wall; 112: stepped portion; 113: adhesive; 114: external terminal; 115: sealing portion; 116: through-hole; 120: cover portion; 121: joining member; 130: internal space; 200: physical quantity sensor device; 210: circuit substrate; 220: connector substrate; 230: package base; 240: cover. DETAILED DESCRIPTION

[0021] 1. First Embodiment

[0022] 1.1. Physical Quantity Sensor

[0023] First, as the physical quantity sensor 10 of the first embodiment, an acceleration sensor that detects acceleration in the vertical direction is exemplified, and the description is made with reference to Figure 1 , Figure 2 and Figure 3 .

[0024] In addition, for the convenience of explanation, the X axis, the Y axis, and the Z axis are illustrated as three axes orthogonal to each other in the following perspective view, plan view, and sectional view. Further, the direction along the X axis is referred to as the "X direction", the direction along the Y axis is referred to as the "Y direction", and the direction along the Z axis is referred to as the "Z direction". Further, the arrow side of each axis is referred to as the "positive side", and the side opposite to the arrow is referred to as the "negative side". Further, the Z direction positive side is referred to as the "up", and the Z direction negative side is referred to as the "down". Further, the Z direction is along the vertical direction, and the XY plane is along the horizontal plane. Further, in the present specification, the positive Z direction and the negative Z direction are collectively referred to as the Z direction.

[0025] The physical quantity sensor 10 of the present embodiment is capable of detecting acceleration in the vertical direction, that is, the Z direction of the physical quantity detection element 60 as a physical quantity. As shown in Figure 1 , such a physical quantity sensor 10 has the physical quantity detection element 60, the cantilever 15 that fixes the physical quantity detection element 60, and the mass portion 70 that becomes a counterweight.

[0026] The cantilever 15 is composed of a quartz substrate, as shown in Figure 2As shown, the base portion 20, the arm portions 30, the movable portion 40, and the narrowed portion 50 are provided.

[0027] The base portion 20 is connected at both ends in the X direction to the arm portions 30, i.e., the first arm portion 31, the second arm portion 32, and the third arm portion 33. In addition, the first arm portion 31 extending to the positive side in the Y direction is connected at one end of the base portion 20, and the second arm portion 32 extending to the positive side in the Y direction and the third arm portion 33 extending to the negative side in the Y direction are connected at the other end of the base portion 20.

[0028] The base end portions of the first arm portion 31, the second arm portion 32, and the third arm portion 33 are connected to the base portion 20, and the first fixing portion 81, the second fixing portion 82, and the third fixing portion 83, which are fixing portions 80, are provided at the free end portions, respectively. In addition, the second arm portion 32 is formed with thin wall portions 85, 86 at two portions between the base portion 20 and the fixing portion 82. The thin wall portions 85, 86 are portions thinner than other portions in the thickness direction of the second arm portion 32, i.e., the Z direction. In addition, in the present embodiment, the thin wall portions 85, 86 are provided at two portions between the base portion 20 and the second fixing portion 82 of the second arm portion 32, but are not limited thereto, and can be provided at three or more portions.

[0029] The movable portion 40 is disposed between the first arm portion 31 and the second arm portion 32 and between the first arm portion 31 and the third arm portion 33 in plan view from the Z direction.

[0030] The narrowed portion 50 is disposed between the base portion 20 and the movable portion 40 and connects the base portion 20 and the movable portion 40.

[0031] The physical quantity detection element 60 is constituted of, for example, a double-prong type quartz resonator, and detects, for example, acceleration or pressure as a physical quantity. The physical quantity detection element 60 is disposed across the narrowed portion 50 in plan view from the Z direction, and is attached to the base portion 20 and the movable portion 40 via an adhesive or the like bonding member 61 (see Figure 6 ).

[0032] The mass portion 70 is constituted of, for example, a metal such as SUS or copper, and is bonded to the upper surface of the free end portion side of the movable portion 40 via a bonding member 74 as shown in Figure 1 . In addition, the mass portion 70 is not limited to being bonded to the upper surface side of the movable portion 40, but can be bonded to the lower surface side of the movable portion 40 (see Figure 6 ). In addition, the mass portion 70 moves up and down together with the movable portion 40, but the both end portions 71, 72 of the mass portion 70 function as stoppers that prevent excessive amplitude by coming into contact with the first arm portion 31 and the second arm portion 32.

[0033] Here, the movable portion 40 is displaced, for example, in accordance with a physical quantity such as acceleration, pressure, and the like, using the narrowed portion 50 as a fulcrum, thereby generating stress in the physical quantity detection element 60 mounted to the base portion 20 and the movable portion 40. In correspondence with the stress applied to the physical quantity detection element 60, the resonance frequency of the vibration frequency of the physical quantity detection element 60 changes. Based on the change in the resonance frequency, the physical quantity can be detected.

[0034] Next, the effects of the thin-walled portions 85, 86 formed in the second arm portion 32 will be described.

[0035] In the case where the fixed portion 80 of the physical quantity sensor 10 is fixed to a package or the like via an adhesive or the like, there is a possibility that stress at the time of fixing, external force applied to the package, stress accompanying a difference in thermal expansion of the cantilever 15 and the package due to external temperature changes, and the like are transmitted to the physical quantity detection element 60 via the fixed portion 80, thereby degrading the temperature characteristics, the aging characteristics of the physical quantity sensor 10.

[0036] Therefore, the physical quantity sensor 10 of the present embodiment is formed with the thin-walled portions 85, 86 in the second arm portion 32 in order to reduce the influence of stress from a package or the like. Figure 3 is a graph showing stress on the physical quantity detection element 60 in the case where the thin-walled portions 85, 86 are formed in the second arm portion 32 and in the case where the thin-walled portions 85, 86 are not formed. When the case where there are no thin-walled portions 85, 86 is taken as a reference of 100%, in the case where there are thin-walled portions 85, 86, it becomes 9.6%, and it is possible to reduce stress applied to the physical quantity detection element 60 by about 90% compared to the case where there are no thin-walled portions 85, 86. Therefore, by forming the thin-walled portions 85, 86 in the second arm portion 32, it is possible to reduce degradation of the temperature characteristics, the aging characteristics in the case where fixed to a package or the like.

[0037] As described above, since the physical quantity sensor 10 of the present embodiment is formed with the thin-walled portions 85, 86 having a smaller thickness than other portions at two portions between the base portion 20 and the second fixed portion 82 of the second arm portion 32, it is possible to moderate stress from a package or the like at the time of fixing the fixed portion 80, and it is possible to reduce degradation of the temperature characteristics, the aging characteristics. Therefore, it is possible to obtain a physical quantity sensor 10 having excellent temperature characteristics, aging characteristics.

[0038] 2. Second Embodiment

[0039] Next, the configuration of the physical quantity sensor 10a of the second embodiment will be described with reference to Figure 4 The physical quantity sensor 10a of the second embodiment will be described.

[0040] In addition, Figure 4 is a plan view showing a simple structure of the cantilever 15a in the physical quantity sensor 10a of the second embodiment.

[0041] The physical quantity sensor 10a of the present embodiment is the same as the physical quantity sensor 10 of the first embodiment except for the structure of the cantilever 15a. The same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0042] As shown in FIG. 8, the cantilever 15a of the physical quantity sensor 10a is formed with thin wall portions 85a, 86a at two portions between the base portion 20 and the second fixed portion 82 of the second arm portion 32. The thin wall portions 85a, 86a are portions that are thinner than other portions in the width direction of the second arm portion 32, i.e., the X direction. In the present embodiment, the thin wall portions 85a, 86a are provided at two portions between the base portion 20 and the second fixed portion 82 of the second arm portion 32, but the present embodiment is not limited thereto, and the thin wall portions can be provided at three or more portions. Figure 4 By being configured as such, the same effects as the physical quantity sensor 10 of the first embodiment can be obtained.

[0043] Further, since the width dimension of the thin wall portions 85a, 86a can be processed with high precision by photolithography and etching techniques, the instability of the temperature characteristics and the aging characteristics can be reduced.

[0044] 3. Third Embodiment

[0045] Next, the physical quantity sensor 10b of the third embodiment will be described with reference to FIG. 9.

[0046] Figure 5 Further, FIG. 10 is a plan view showing a simple structure of the cantilever 15b in the physical quantity sensor 10b of the third embodiment.

[0047] Further, FIG. 10 is a plan view showing a simple structure of the cantilever 15b in the physical quantity sensor 10b of the third embodiment. Figure 5 The physical quantity sensor 10b of the present embodiment is the same as the physical quantity sensor 10 of the first embodiment except for the structure of the cantilever 15b. The same components as those of the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0048] As shown in FIG. 10, the cantilever 15b of the physical quantity sensor 10b is formed with thin wall portions 85b, 86b at two portions between the base portion 20 and the second fixed portion 82 of the second arm portion 32. The thin wall portions 85b, 86b are portions that are thinner than other portions in the width direction of the second arm portion 32, i.e., the X direction. In the present embodiment, the thin wall portions 85b, 86b are provided at two portions between the base portion 20 and the second fixed portion 82 of the second arm portion 32, but the present embodiment is not limited thereto, and the thin wall portions can be provided at three or more portions.

[0049] Figure 5 ​​As shown, the physical quantity sensor 10b has thin-walled portions 85b and 86b formed at two locations between the base 20 of the third arm 33 and the third fixing portion 83. The thin-walled portions 85b and 86b are thinner than other portions in the thickness direction (Z direction) of the third arm 33. Furthermore, in this embodiment, the thin-walled portions 85b and 86b are provided at two locations between the base 20 of the third arm 33 and the third fixing portion 83, but this is not a limitation; thin-walled portions may be provided at three or more locations.

[0050] By configuring it in this way, the same effect as the physical quantity sensor 10 of the first embodiment can be obtained.

[0051] 4. Fourth Implementation Method

[0052] 4.1. Physical quantity sensor device

[0053] Next, refer to Figure 6 The physical quantity sensor device 100 equipped with the physical quantity sensors 10, 10a, and 10b of the fourth embodiment will be described. Furthermore, in the following description, the structure in which the physical quantity sensor 10 is applied will be illustrated.

[0054] The physical quantity sensor device 100 includes a physical quantity sensor 10, a base 110 on which the physical quantity sensor 10 is mounted, and a cover portion 120 that serves as a cover. In this embodiment, the base 110 is configured as an encapsulation base including a bottom wall 110A and a side wall 110B. The base 110 and the cover portion 120 together form an encapsulation for housing the physical quantity sensor 10. The cover portion 120 is engaged with the open end of the base 110 via a joining member 121 such as glass powder or a sealing ring. Furthermore, the physical quantity in the physical quantity sensor device 110 of this embodiment refers to acceleration.

[0055] On the bottom wall 110A of the base 110, a stepped portion 112, one step higher than the inner surface 110A1 of the bottom wall 110A, is provided along, for example, three of the four side walls 110B. The stepped portion 112 can protrude from the inner surface of the side wall 110B, or it can be integral with or separate from the base 110, forming part of the base 110. Figure 6 As shown, the physical quantity sensor 10 is fixed to the stepped portion 112 by an adhesive 113. Specifically, the fixing portion 80 of the physical quantity sensor 10 is mounted on the stepped portion 112 of the base 110. Here, the adhesive 113 is preferably a resin-based adhesive with a high elastic modulus, such as epoxy resin. This is because adhesives such as low-melting-point glass are hard and cannot absorb the stress and strain generated during bonding, which would have an adverse effect on the physical quantity sensing element 60.

[0056] In this embodiment, such as Figure 1As shown, the physical quantity sensing element 60 can be connected to an electrode, such as a gold electrode, formed on the step portion 112 via a bonding wire 62. In this case, it is not necessary to form an electrode pattern on the base 20. However, it is also possible to avoid using the bonding wire 62 and instead connect the electrode pattern provided on the base 20 to the electrode formed on the step portion 112 of the base 110 via a conductive adhesive.

[0057] On the outer surface 110A2, opposite to the inner surface 110A1, of the bottom wall 110A of the base 110, there is an external terminal 114 for use when mounted on a circuit board (not shown). The external terminal 114 is electrically connected to the physical quantity detection element 60 via wiring, electrodes (not shown).

[0058] For example, a sealing portion 115 is provided on the bottom wall 110A, which provides an airtight seal to the internal space 130 of the encapsulation formed by the base 110 and the cover 120. The sealing portion 115 is provided within a through hole 116 formed in the base 110. The sealing portion 115 is provided by placing a sealing material in the through hole 116 and then solidifying the sealing material after heating and melting it.

[0059] As described above, since the physical quantity sensor device 100 of this embodiment has a physical quantity sensor 10 with excellent temperature characteristics and aging characteristics, it can detect acceleration with high accuracy.

[0060] 4.2. Manufacturing method of physical quantity sensor device

[0061] Next, refer to Figure 7 The manufacturing method of the physical quantity sensor device 100 of this embodiment will be described. Furthermore, in the following description, a manufacturing method using the physical quantity sensor 10 will be illustrated and explained.

[0062] like Figure 7 As shown, the manufacturing method of the physical quantity sensor device 100 in this embodiment includes a physical quantity detection element preparation process, a cantilever preparation process, an element bonding process, a mass part bonding process, a cantilever bonding process, a bonding process, a cover part bonding process, and a sealing process.

[0063] 4.2.1. Preparation process for physical quantity detection elements

[0064] First, in step S1, the quartz substrate is processed by photolithography and etching techniques, and a double tuning fork type quartz resonator is prepared as a physical quantity detection element 60.

[0065] 4.2.2. Cantilever preparation process

[0066] In step S2, the quartz substrate is processed by a photolithography technique and an etching technique, and a cantilever 15 having a base portion 20, an arm portion 30, a movable portion 40, a narrowed portion 50, thin wall portions 85, 86, a first fixed portion 81, a second fixed portion 82, and a third fixed portion 83 is prepared.

[0067] 4.2.3. Element Bonding Step

[0068] In step S3, one end portion of the physical quantity detecting element 60 is bonded to the upper surface of the base portion 20 of the cantilever 15 via a bonding member 61, and the other end portion of the physical quantity detecting element 60 is bonded to the upper surface of the movable portion 40 of the cantilever 15.

[0069] 4.2.4. Mass Portion Bonding Step

[0070] In step S4, the mass portion 70 is bonded to the upper surface and the lower surface of the free end portion side of the movable portion 40 of the cantilever 15 via a bonding member 74.

[0071] 4.2.5. Cantilever Bonding Step

[0072] In step S5, the cantilever 15 in which the physical quantity detecting element 60 and the mass portion 70 are bonded is bonded to the base 110. Specifically, the first fixed portion 81, the second fixed portion 82, and the third fixed portion 83 of the physical quantity sensor 10 are fixed to the stepped portion 112 of the base 110 via an adhesive 113.

[0073] 4.2.6. Bonding Step

[0074] In step S6, an electrode provided to the physical quantity detecting element 60 is electrically connected to an electrode formed to the stepped portion 112 of the base 110 by a bonding wire 62.

[0075] 4.2.7. Cover Portion Bonding Step

[0076] In step S7, the cover portion 120 is bonded to the upper surface of the base 110 via a bonding member 121.

[0077] 4.2.8. Sealing Step

[0078] In step S8, a sealing material is disposed to the through hole 116 provided to the bottom wall 110A of the base 110, and after the sealing material is heated and melted, it is solidified, and the internal space 130 in which the physical quantity sensor 10 is accommodated is hermetically sealed.

[0079] Through the above steps, the physical quantity sensor device 100 having the physical quantity sensor 10 having excellent temperature characteristics and aging characteristics and capable of detecting acceleration with high precision is completed.

[0080] 5. Fifth embodiment

[0081] 5.1. Physical quantity sensor device

[0082] Next, referring to Figure 8 The physical quantity sensor device 100a of the fifth embodiment will be described.

[0083] In addition, Figure 8 is a plan view showing a simple structure of the cantilever 15c of the physical quantity sensor 10c provided in the physical quantity sensor device 100a of the fifth embodiment.

[0084] The physical quantity sensor device 100a of the present embodiment is the same as the physical quantity sensor device 100 of the fourth embodiment except that the structure of the cantilever 15c of the physical quantity sensor 10c is different. In addition, the same matters as those of the fourth embodiment described above will be described centering on the difference from the fourth embodiment, and the same reference numerals will be attached to the same matters, and the description thereof will be omitted.

[0085] As Figure 8 shown, in the cantilever 15c of the physical quantity sensor 10c provided in the physical quantity sensor device 100a, the base 20 of the second arm portion 32 is separated from the second fixing portion 82. This is a state in which the thin wall portion 85 formed between the thin wall portion 86 and the thin wall portion 87 of the second arm portion 32 is folded off in the cantilever 15 of the physical quantity sensor 10 of the first embodiment shown in Figure 2 Thus, it is possible to more gently reduce the stress from the package or the like due to the fixing of the fixing portion 80, and it is possible to more reduce the deterioration of the temperature characteristics and the aging characteristics.

[0086] By being configured as such, it is possible to obtain the same effects as the physical quantity sensor device 100 of the fourth embodiment.

[0087] In addition, since the base 20 of the second arm portion 32 is separated from the second fixing portion 82, it is possible to more reduce the deterioration of the temperature characteristics and the aging characteristics.

[0088] 5.2. Manufacturing method of physical quantity sensor device

[0089] Next, referring to Figure 9 The manufacturing method of the physical quantity sensor device 100a of the present embodiment will be described.

[0090] The manufacturing method of the physical quantity sensor device 100a of the present embodiment is the same as the manufacturing method of the physical quantity sensor device 100 of the fourth embodiment except that the separation process of step S16 is added after the cantilever joining process of step S15. The same reference numerals are assigned to the same matters as those of the fourth embodiment, and the description thereof is omitted.

[0091] As shown in Figure 9 , the manufacturing method of the physical quantity sensor device 100a of the present embodiment includes a physical quantity detecting element preparation process, a cantilever preparation process, an element joining process, a mass portion joining process, a cantilever joining process, a separation process, a bonding process, a cap portion joining process, and a sealing process.

[0092] In the separation process of step S16, the thin wall portion 85 formed between the thin wall portion 85 and the thin wall portion 86 of the second arm portion 32 is folded in the state where the physical quantity sensor 10 is assembled to the base 110, specifically, in the state where the first fixing portion 81, the second fixing portion 82, and the third fixing portion 83 of the physical quantity sensor 10 are fixed to the step portion 112 of the base 110. By this process, the physical quantity sensor 10c in which the base portion 20 is separated from the second fixing portion 82 by the second arm portion 32 is obtained. Since the base portion 20 is separated from the second fixing portion 82, the stress from the package or the like due to the fixing of the fixing portion 80 can be more gently reduced. In addition, the present separation process can be performed after the bonding process of step S17.

[0093] By the manufacturing method of the physical quantity sensor device 100a of the present embodiment, the physical quantity sensor device 100a in which the deterioration of the temperature characteristics and the aging characteristics can be more reduced can be obtained.

[0094] 6. Sixth Embodiment

[0095] Next, the physical quantity sensor device 100b of the sixth embodiment will be described with reference to Figure 10 to the sixth embodiment will be described.

[0096] In addition, Figure 10 is a plan view showing a simple structure of the cantilever 15d of the physical quantity sensor 10d provided to the physical quantity sensor device 100b of the sixth embodiment.

[0097] The physical quantity sensor device 100b of this embodiment is the same as the physical quantity sensor device 100 of the fourth embodiment, except that the structure of the cantilever 15d of the physical quantity sensor 10d is different. Furthermore, the description will focus on the differences from the fourth embodiment described above, and the same reference numerals will be used for the same items, so their descriptions are omitted.

[0098] like Figure 10 As shown, in the cantilever 15d of the physical quantity sensor 10d installed in the physical quantity sensor device 100b, the base 20 of the third arm portion 33 is separated from the third fixing portion 83. This is... Figure 5 In the third embodiment of the physical quantity sensor 10b shown, the thin-walled portion 85b and the thin-walled portion 86b formed in the third arm portion 33 are folded away from the cantilever 15b. Therefore, the stress from packaging and the like caused by fixing the fixing portion 80 can be more mitigated, and the deterioration of temperature characteristics and aging characteristics can be further reduced.

[0099] Furthermore, the manufacturing method of the physical quantity sensor device 100b is the same as that of the physical quantity sensor device 100a in the fifth embodiment. In the separation process of step S16, while the physical quantity sensor 10b is assembled on the base 110, the thin-walled portion 85b and the thin-walled portion 86b formed on the third arm portion 33 are folded apart. Through this process, a physical quantity sensor 10d is obtained in which the base portion 20 connected by the third arm portion 33 is separated from the third fixing portion 83, and the physical quantity sensor device 100b can be manufactured.

[0100] By setting the structure in this way, the same effect as the physical quantity sensor device 100 of the fourth embodiment can be obtained.

[0101] Furthermore, since the base 20 of the third arm 33 is separated from the third fixing part 83, the degradation of temperature characteristics and aging characteristics can be further reduced.

[0102] 7. Seventh Implementation Method

[0103] Next, refer to Figure 11 The physical quantity sensor device 200, which includes the physical quantity sensor devices 100, 100a, and 100b of the seventh embodiment, will be described. Furthermore, in the following description, the structure of the physical quantity sensor device 100, which incorporates the physical quantity sensor 10, will be illustrated and explained.

[0104] The physical quantity sensor device 200 has three physical quantity sensor devices 100, which are capable of detecting physical quantities along three orthogonal axes. Furthermore, the physical quantity in the physical quantity sensor device 200 of this embodiment refers to acceleration.

[0105] like Figure 11 As shown, in the physical quantity sensor device 200, three physical quantity sensor devices 100 are mounted on the circuit board 210. The three physical quantity sensor devices 100 are mounted on the circuit board 210 in such a way that their respective detection axes are aligned with three orthogonal axes. The circuit board 210 is electrically connected to the connector board 220. These circuit boards 210 and connector boards 220 are housed in a package formed by the package base 230 and the cover 240.

[0106] As described above, since the physical quantity sensor device 200 of this embodiment is equipped with three physical quantity sensor devices 10 having excellent temperature characteristics and aging characteristics along three orthogonal axes that become detection axes, the acceleration of the three axes can be detected with high precision.

Claims

1. A physical quantity sensor characterized by comprising: comprising: a base; first, second, and third arm portions connected to the base and each provided with a fixed portion; a movable portion disposed between the first and second arm portions and between the first and third arm portions in plan view; a narrowed portion disposed between the base and the movable portion and connecting the base and the movable portion; and a physical quantity detection element disposed across the narrowed portion and mounted to the base and the movable portion in the plan view, in a case where a plane defined by an X direction and a Y direction of the base is taken as a horizontal plane and a direction orthogonal to the X direction and the Y direction is taken as a Z direction, the first arm portion is disposed extending along a positive side of the Y direction at one end of the X direction of the base, the second arm portion is disposed extending along the positive side of the Y direction at an opposite end of the X direction of the base, the third arm portion is disposed extending along a negative side of the Y direction at the opposite end of the X direction of the base, in the second and third arm portions, thin wall portions are formed at at least three points between the base and the fixed portions in the plan view from the Z direction, the thin wall portions are portions thinner than other portions in the Z direction of the second and third arm portions. comprising:

2. A physical quantity sensor device, characterized by, the physical quantity sensor of claim 1; and a base provided with the physical quantity sensor, the fixed portion is mounted to the base.

3. The physical quantity sensor device according to claim 2, characterized in that the physical quantity sensor device includes a circuit board, and has three of the physical quantity sensors, the three physical quantity sensors are mounted to the circuit board in a manner that respective detection axes coincide with three orthogonal axes, respectively.

4. The physical quantity sensor device according to claim 2 or 3, characterized in that the physical quantity to be detected is acceleration. is a manufacturing method of the physical quantity sensor device of claim 2, the manufacturing method including the following steps: preparing a physical quantity detection element; 5. A method of manufacturing a physical quantity sensor device, characterized by preparing a cantilever provided with a base, a first fixed portion, a second fixed portion, and a third fixed portion; joining the physical quantity detection element and the cantilever; mounting the first, second, and third fixed portions to a base; and in the mounted state, breaking off between the thin wall portions formed in the second arm portion to separate the second fixed portion from the base, or breaking off between the thin wall portions formed in the third arm portion to separate the third fixed portion from the base. ​ ​

Images