JP6432652B2 - Manufacturing method of vibrating piece - Google Patents

Description

  The present invention relates to a resonator element, a method for manufacturing the resonator element, a vibrator, an electronic device, a gyro sensor, an electronic apparatus, and a moving body.

Conventionally, a so-called “double T-type” gyro element is known as a vibrating piece for detecting angular velocity (see, for example, Patent Document 1).
The gyro element described in Patent Document 1 includes a base, first and second detection vibrating arms (detection arms) extending along the y-axis from the base to both sides, and along the x-axis from the base to both sides. Extending first and second connecting arms (connecting arms), first and second driving vibrating arms (driving arms) extending from the first connecting arms to both sides along the y-axis, and second It is comprised by the 3rd, 4th drive vibration arm (drive arm) extended along the y-axis from the connection arm to both sides.
And the weight layer provided toward the base from the front-end | tip of each drive vibration arm is provided in the front-end | tip part of the 1st, 2nd, 3rd, 4th drive vibration arm. This weight layer is a mass adjustment film used for resonance frequency adjustment (hereinafter referred to as frequency adjustment) of each drive vibrating arm, and is formed by an evaporation method using an evaporation mask. In the frequency adjustment, at least a part of the weight layer is removed by using, for example, a laser beam, and the resonance frequency of each drive vibrating arm is adjusted to a predetermined value.

JP 2006-105614 A

However, when the weight layer of each vibrating arm is formed by the vapor deposition method using the vapor deposition mask as described above, the mounting position of the vapor deposition mask may vary. In particular, when the mounting position of the vapor deposition mask is shifted in the extending direction (y-axis direction) of each driving vibration arm (vibrating arm), each driving vibration arm is extended from the base to both sides (opposite directions). For example, in the first drive vibration arm and the second drive vibration arm, if the weight layer of the first drive vibration arm is increased, the weight layer of the second drive vibration arm is decreased.
Thus, when the mounting position of the vapor deposition mask is shifted in the extending direction (y-axis direction) of each driving vibration arm, the size of the weight layer formed on the driving vibration arms extending in the opposite directions to each other, The mass is different (becomes unbalanced). That is, the gravity center position and the mass of the weight layer provided in each drive vibrating arm extending in the opposite directions are different. As a result, the vibration balance of the drive vibrating arms extending in the opposite directions is lost, and the deterioration of the frequency temperature characteristics, so-called temperature drift, may occur.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

  Application Example 1 The resonator element according to this application example includes a base, a pair of vibrating arms extending in the opposite direction from the base, and a distance from at least one tip of the vibrating arm toward the base. A first weight portion provided on the at least one vibrating arm, and a first portion provided in a region between the tip of the first weight portion and the tip of the at least one vibrating arm. An area between the tip of the first weight part and the tip of the at least one of the vibrating arms is a second area. When the area of the first region is A1, the mass of the first weight portion is B1, the area of the second region is A2, and the mass of the second weight portion is B2, B1 / A1> B2 / It is A2.

The inventor of the present application has unbalanced the gravity center position of the weight layer in relation to the weight drift (the weight part obtained by adding the first weight part and the second weight part) provided on the vibrating arm and the temperature drift of the vibrating piece. It was found that there is an effect on temperature drift due to (position change of the weight layer) and an effect on temperature drift due to mass imbalance of the weight layer. Here, the temperature drift means that the frequency of the resonator element changes with respect to the temperature change.
More specifically, the mass imbalance of the weight layer has a greater influence on the temperature drift than the imbalance of the weight layer position, and the closer the weight layer position is to the tip of the vibrating arm, the more the influence on the temperature drift. The degree is increased. Furthermore, the correlation between the mass unbalance of the weight layer and the temperature drift of the vibrating piece has a negative slope, and the correlation between the position imbalance of the weight layer and the temperature drift of the vibrating piece has a positive slope. It has a correlation with That is, by using the weight layer having the above-described configuration, the temperature drift due to the mass unbalance of the weight layer and the temperature drift due to the influence of the position unbalance of the weight layer are offset, thereby generating the temperature drift. We found that it is possible to reduce.

In the resonator element of this application example, since the pair of vibrating arms extends from the base toward the opposite directions, when the mounting position of the vapor deposition mask is shifted in the extending direction of each vibrating arm, The position of the first weight portion provided on the vibrating arm is formed so as to be shifted toward the distal end side in one vibrating arm, and shifted to the base side in the other vibrating arm.
Here, the first weight part is provided in the first region of the vibrating arm at a distance from the tip of the vibrating arm, and the second weight part is all between the first weight part and the tip of the vibrating arm. Provided in the second region, that is, on the tip side of the vibrating arm from the first weight portion, the area of the first region is A1, the mass of the first weight portion is B1, and the area of the second region Is A2, and the mass of the second weight portion is B2, B1 / A1> B2 / A2.

With this configuration, since the mass of the second weight portion having a large influence on the occurrence of temperature drift of the vibrating piece is reduced, the negative slope in the correlation between the mass imbalance and the temperature drift of the vibrating piece is reduced. At this time, since the first weight portion is formed with a position shifted in one and the other vibrating arms, the first weight portion is affected by the temperature drift of the vibrating piece due to the position unbalance. The positive slope in the correlation with the temperature drift is not changed.
Therefore, in the above configuration, the negative slope, which is reduced in the correlation with the temperature drift of the vibrating piece due to the mass unbalance of the second weight portion, and the correlation between the position unbalance of the first weight portion and the temperature drift of the vibrating piece. The originally small positive slope in the case of positive and negative has almost the same slope. As a result, the correlation between the temperature drift of the vibrating piece due to mass imbalance and the correlation between the position imbalance and the temperature drift of the vibrating piece are offset, and the deposition mask mounting position is shifted in the extending direction of each vibrating arm. That is, even when the positions of the first weight part and the second weight part provided on the respective vibrating arms are shifted, it is possible to suppress the occurrence of temperature drift of the vibrating piece.
This configuration may be applied to both the pair of vibrating arms, but may be applied to one vibrating arm located on the opposite side of the pair of vibrating arms from the direction in which the weight portion is displaced. As a result, the above-described effects can be produced. That is, the weight part of this configuration may be applied to one vibrating arm located on the opposite side to the direction in which the weight part is displaced.

  Application Example 2 In the resonator element according to the application example described above, the second weight portion has a width in a direction perpendicular to the extending direction of the at least one vibrating arm, than the width of the first weight portion. Is also small.

  According to this application example, it is possible to reduce the negative slope in the correlation with the temperature drift of the vibrating piece due to the mass imbalance of the second weight portion having a large influence on the occurrence of the temperature drift of the vibrating piece. In other words, even if the positions of the first weight part and the second weight part provided on the respective vibrating arms are displaced due to the attachment position of the vapor deposition mask being displaced in the extending direction of each vibrating arm, the vibrating piece It is possible to suppress the occurrence of temperature drift.

  Application Example 3 In the resonator element according to the application example described above, the second weight portion has a substantially central portion of the at least one vibrating arm in a direction orthogonal to the extending direction of the at least one vibrating arm. It is provided in.

  According to this application example, since the balance in the width direction of the vibrating arm of the second weight portion can be achieved, it is possible to further suppress the influence on the temperature drift of the vibrating piece.

  Application Example 4 In the resonator element according to the application example, the second weight portion includes a plurality of third weight portions.

  According to this application example, since the second weight portion includes a plurality of third weight portions, due to the mass unbalance of the second weight portion having a large influence on the occurrence of the temperature drift of the resonator element. The negative slope in the correlation with the temperature drift of the resonator element can be reduced.

  Application Example 5 In the resonator element according to the application example described above, the first weight portion is between a side end of the at least one vibrating arm along the extending direction of the at least one vibrating arm. It is characterized by being provided at intervals.

  According to this application example, even when the mounting position of the vapor deposition mask is shifted in the width direction of each vibrating arm, there is a gap between the first weight portion and the side end of the vibrating arm. It is possible to suppress detachment from the arm. Therefore, even when the first weight portion is displaced in the width direction of each vibrating arm, it is possible to prevent the mass change of the first weight portion from occurring.

  Application Example 6 In the resonator element according to the application example described above, the at least one vibrating arm includes the at least one vibrating arm in a direction orthogonal to an extending direction of the at least one vibrating arm in a plan view. A width portion of which the first weight is formed wider than the width of the other portion of the at least one vibrating arm in a direction orthogonal to the extending direction of the at least one vibrating arm, The portion and the second weight portion are provided in the wide portion.

  According to this application example, the masses of the first weight part and the second weight part can be increased, and the frequency adjustment range can be widened.

  Application Example 7 In the resonator element according to the application example described above, a pair of detection vibrating arms extending in opposite directions from the base portion are provided.

  According to this application example, even when the positions of the first weight part and the second weight part provided on the respective vibrating arms are shifted due to the mounting position of the vapor deposition mask being shifted in the extending direction of each vibrating arm. In addition, it is possible to provide a gyro vibrating piece capable of suppressing the occurrence of temperature drift in the vibrating piece.

  Application Example 8 A method of manufacturing a resonator element according to this application example includes a step of forming an outer shape including a base portion and a pair of vibrating arms extending from the base portion in opposite directions, and at least A distance from the tip of one of the vibrating arms to the base side, the at least one of the vibrating arms includes a first weight portion, a tip of the first weight portion, and a tip of the at least one of the vibrating arms. A step of forming a second weight portion in a region therebetween, and at least a part of at least one of the first weight portion and the second weight portion is removed, or the first weight portion and the second weight portion are removed. Adding a mass of at least one of the weight portions to adjust the resonance frequency of the vibrating arm, wherein the region where the first weight portion is provided is a first region, and the tip of the first weight portion A region between the tip of the at least one vibrating arm is a second region. When the area of the first region is A1, the mass of the first weight portion is B1, the area of the second region is A2, and the mass of the second weight portion is B2, B1 / A1> B2 / It is formed by A2.

  According to this application example, a resonator element having a small negative slope in the correlation with the temperature drift of the resonator element due to the mass imbalance of the second weight portion having a large influence on the occurrence of the temperature drift of the resonator element is manufactured. Is possible. In other words, even if the positions of the first weight part and the second weight part provided on the respective vibrating arms are displaced due to the attachment position of the vapor deposition mask being displaced in the extending direction of each vibrating arm, the vibrating piece Thus, it is possible to manufacture a resonator element that can suppress the occurrence of temperature drift.

  Application Example 9 In the method for manufacturing a resonator element according to the application example described above, the step of forming the first weight part and the second weight part includes a distance from the tip of at least one of the vibrating arms to the base side. And forming a first weight portion on the at least one vibrating arm, and forming a second weight portion in a region between the tip of the first weight portion and the tip of the at least one vibrating arm. And a step of performing.

  According to this application example, even when the mounting position of the vapor deposition mask is shifted in the extending direction of each vibrating arm and the positions of the first weight portion and the second weight portion provided on each vibrating arm are shifted, the vibrating piece Thus, it is possible to manufacture a resonator element that can suppress the occurrence of temperature drift. In addition, since the first weight portion and the second weight portion can be formed in separate steps, for example, it is possible to cope with changing the material of each weight portion, changing the thickness of each weight portion, or the like.

  Application Example 10 A vibrator according to this application example includes the resonator element according to any one of the application examples described above and a package in which the resonator element is stored.

  According to this application example, it is possible to provide a vibrator in which the occurrence of temperature drift of the resonator element is suppressed, that is, the temperature characteristics are improved.

  Application Example 11 An electronic device according to this application example includes the resonator element according to any one of the application examples described above and a circuit element having a function of driving at least the resonator element. It is characterized by.

  According to this application example, it is possible to provide an electronic device in which occurrence of temperature drift is suppressed and temperature characteristics are improved.

  Application Example 12 An electronic apparatus according to this application example includes the resonator element according to any one of the application examples described above.

  According to this application example, the use of the resonator element in which the occurrence of temperature drift is suppressed and the temperature characteristics are improved, an electronic apparatus having stable characteristics with respect to temperature changes can be provided.

  Application Example 13 A moving body according to this application example includes the resonator element according to any one of the application examples described above.

  According to this application example, the use of the resonator element in which the occurrence of temperature drift of the resonator element is suppressed and the temperature characteristics are improved can provide a moving body with stable characteristics with respect to temperature change. .

It is the schematic which shows embodiment of the resonator element concerning this invention, and embodiment of the vibrator | oscillator using the resonator element, (A) is a top view, (B) is a front sectional view. The top view of the gyro element as a vibration piece with which a vibrator | oscillator is provided. The top view explaining the drive of a gyro element. It is a figure explaining the relationship between the conventional weight part and the temperature drift of a gyro element, (A) is a partial top view which shows the form of a weight part, (B) is the deviation | shift amount and temperature drift amount of a weight part. Graph showing correlation. It is a figure explaining the relationship between the weight part of this embodiment, and the temperature drift of a gyro element, (A) is a fragmentary top view which shows the form of a weight part, (B) is the deviation | shift amount and temperature drift amount of a weight part. A graph showing the correlation. It is a figure explaining the relationship between the weight part of this embodiment, and the temperature drift of a gyro element, (A) is a fragmentary top view which shows the form of a weight part, (B) is the deviation | shift amount and temperature drift amount of a weight part. A graph showing the correlation. It is a figure explaining the relationship between the weight part of this embodiment, and the temperature drift of a gyro element, (A) is a fragmentary top view which shows the form of a weight part, (B) is the deviation | shift amount and temperature drift amount of a weight part. The graph which shows a correlation with (C) is an enlarged plan view which shows the detail of the shape of a weight part. (A)-(E) are the partial top views which show the modification of a weight part. (A)-(C) are the top view and sectional drawing which show the modification of a weight part. 6 is a flowchart showing a method for manufacturing a resonator element according to the invention. FIG. 5 is a front sectional view showing an electronic device using the resonator element according to the invention. The perspective view which shows the structure of the mobile type personal computer as an example of an electronic device. The perspective view which shows the structure of the mobile telephone as an example of an electronic device. The perspective view which shows the structure of the digital still camera as an example of an electronic device. The perspective view which shows the structure of the motor vehicle as an example of a mobile body.

Hereinafter, a resonator element and a vibrator of the present invention will be described in detail based on embodiments shown in the accompanying drawings.
<Embodiment>
First, an embodiment of a resonator element according to the invention and an embodiment of a vibrator to which the resonator element is applied will be described.

  1A and 1B are diagrams showing an embodiment of a resonator element according to the invention and a vibrator using the resonator element, wherein FIG. 1A is a plan view and FIG. 1B is a front sectional view. FIG. 2 is a plan view showing a gyro element as a resonator element included in the vibrator shown in FIG. FIG. 3 is a plan view for explaining driving of the gyro element. In the following, as shown in FIG. 1, three axes orthogonal to each other are defined as an x-axis, a y-axis, and a z-axis, and the z-axis coincides with the thickness direction of the vibration device. A direction parallel to the x-axis is referred to as an “x-axis direction (second direction)”, a direction parallel to the y-axis is referred to as a “y-axis direction (first direction)”, and a direction parallel to the z-axis is “ z-axis direction ".

  A vibrator 1 shown in FIG. 1 includes a gyro element (vibration element) 2 as a vibration piece and a package 9 that houses the gyro element 2. Hereinafter, the gyro element 2 and the package 9 will be sequentially described in detail.

(Gyro element)
FIG. 2 is a plan view of a gyro element as a resonator element viewed from above (from the lid 92 side). The gyro element includes a detection signal electrode, a detection signal wiring, a detection signal terminal, a detection ground electrode, a detection ground wiring, a detection ground terminal, a drive signal electrode, a drive signal wiring, a drive signal terminal, a drive ground electrode, and a drive ground wiring. In addition, a driving ground terminal and the like are provided, but are omitted in the figure.

The gyro element 2 as a vibrating piece is an “out-of-plane detection type” sensor that detects an angular velocity around the z axis, and although not shown, a base material and a plurality of electrodes provided on the surface of the base material, It consists of wiring and terminals.
The gyro element 2 can be made of a piezoelectric material such as quartz, lithium tantalate, or lithium niobate. Among these, it is preferable that the gyro element 2 is made of quartz. Thereby, the gyro element 2 which can exhibit the outstanding vibration characteristic (frequency characteristic) is obtained.
Such a gyro element 2 includes a so-called double T-shaped vibrating body 4, a first supporting portion 51 and a second supporting portion 52 as supporting portions for supporting the vibrating body 4, the vibrating body 4, the first and first 2 It has the 1st beam 61, the 2nd beam 62, the 3rd beam 63, and the 4th beam 64 as a beam which connects the support parts 51 and 52.

  The vibrating body 4 has an extension in the xy plane and has a thickness in the z-axis direction. Such a vibrating body 4 includes a base 41 located at the center, a first detection vibrating arm 421 and a second detection vibrating arm 422 extending from the base 41 to both sides along the y-axis direction, and an x from the base 41. A first connecting arm 431 and a second connecting arm 432 that extend to both sides along the axial direction, and a vibrating arm that extends from the tip of the first connecting arm 431 to both sides along the y-axis direction. A first driving vibrating arm 441, a second driving vibrating arm 442, a third driving vibrating arm 443 as a vibrating arm extending from the tip of the second connecting arm 432 to both sides along the y-axis direction, and a fourth driving arm 443; And a drive vibrating arm 444. The distal ends of the first and second detection vibrating arms 421 and 422 and the first, second, third, and fourth driving vibrating arms 441, 442, 443, and 444 are substantially larger in width than the base end side, respectively. Weight portions (hammer heads) 425, 426, 445, 446, 447, and 448 as rectangular wide portions are provided. By providing such weight parts 425, 426, 445, 446, 447, 448, the sensitivity of detecting the angular velocity of the gyro element 2 is improved.

The first and second drive vibrating arms 441 and 442 may extend from the middle of the extending direction of the first connecting arm 431. Similarly, the third and fourth drive vibrating arms 443 and 444 You may extend from the middle of the extension direction of the 2 connection arms 432.
Further, in this example, the first connecting arm 431 extending from the base 41, the first connecting vibrating arm 441, the second driving vibrating arm 442, the third driving vibrating arm 443, and the fourth driving from the second connecting arm 432 are provided. Although the configuration in which the vibrating arm 444 extends has been described, the base 41, the first connecting arm 431, and the second connecting arm 432 may be used as the base. That is, a configuration in which the first drive vibration arm, the second drive vibration arm, the third drive vibration arm, and the fourth drive vibration arm extend from the base is also possible.
Further, the first and second support portions 51 and 52 respectively extend along the x-axis direction, and the vibrating body 4 is located between the first and second support portions 51 and 52. . In other words, the first and second support portions 51 and 52 are disposed so as to face each other along the y-axis direction with the vibrating body 4 interposed therebetween. The first support 51 is connected to the base 41 via the first beam 61 and the second beam 62, and the second support 52 is connected to the base 41 via the third beam 63 and the fourth beam 64. It is connected with.

  The first beam 61 passes between the first detection vibrating arm 421 and the first drive vibrating arm 441 to connect the first support portion 51 and the base 41, and the second beam 62 is connected to the first detection vibrating arm 421. The first support part 51 and the base part 41 are connected to each other through the third drive vibration arm 443, and the third beam 63 passes between the second detection vibration arm 422 and the second drive vibration arm 442. The second support portion 52 and the base portion 41 are connected, and the fourth beam 64 connects the second support portion 52 and the base portion 41 through the space between the second detection vibration arm 422 and the fourth drive vibration arm 444.

  Each of the beams 61, 62, 63, 64 has a meandering portion (S-shaped portion) extending along the y-axis direction while reciprocating along the x-axis direction. It has elasticity in the y-axis direction. Further, each beam 61, 62, 63, 64 has an elongated shape having a meandering portion, and therefore has elasticity in all directions. Therefore, even if an impact is applied from the outside, each beam 61, 62, 63, 64 has an action of absorbing the impact, so that detection noise caused by this can be reduced or suppressed.

(Weight part of gyro element)
In the weight part 425 of the first detection vibrating arm 421 and the weight part 426 of the second detection vibrating arm 422, the natural resonance frequencies of the first detection vibrating arm 421 and the second detection vibrating arm 422 are adjusted to a desired frequency. Detection arm weight layers 14 and 15 for mass adjustment are provided.

  The weight portion 445 of the first drive vibrating arm 441 is provided with a weight portion 13c. The weight portion 13 c includes a first weight portion 12 c provided in a first region of the first drive vibrating arm 441 and a distance from the tip of the first drive vibrating arm 441 toward the base 41, and the first drive vibrating arm 441. A second weight portion 11c provided in a second region between the tip and an end of the first weight portion 12c on the tip side of the first drive vibrating arm 441 (hereinafter referred to as “the tip of the first weight portion 12c”); , Including.

  The first region is a region having a quadrangular area A1 spaced from the tip of the first drive vibrating arm 441 (tip of the weight portion 445) and both sides of the weight portion 445. The first weight portion 12c is a quadrilateral that substantially overlaps the first region, and is provided with a mass B1. In FIG. 2, the first region is indicated by cross hatching.

  The second region is a region of area A2 provided in the second region, which is a region between the tip of the first weight portion 12c and the tip of the first drive vibrating arm 441 facing the tip of the first weight portion 12c. It is. The second weight portion 11c is located in the second region from the substantially central portion in the width direction (x-axis direction) of the first weight portion 12c on the distal end side of the first drive vibration arm 441. The quadrilateral is narrower than the first weight portion 12c reaching the tip, and is provided with a mass B2.

  As described above, the weight portion 13 c is formed in a convex shape toward the distal end side of the first drive vibrating arm 441. The weight portion 13c has an area A1 of the first region, an area A2 of the second region, a mass B1 of the first weight portion 12c, and a mass B2 of the second weight portion 11c such that B1 / A1> B2 / A2. Is provided. In this example, the first weight portion 12c and the second weight portion 11c are formed with the same thickness, and the first weight portion 12c is provided in substantially the same shape as the first region in order to satisfy the above relational expression. The second weight portion 11c is provided so that the width of the second weight portion 11c is narrower than the width of the second region.

  Similarly, the weight portion 446 of the second drive vibrating arm 442 is provided with a weight portion 13d. The weight portion 13d includes a first weight portion 12d provided in a first region of the second drive vibration arm 442 and a distance from the tip of the second drive vibration arm 442 toward the base 41, and the second drive vibration arm 442. A second weight portion 11d provided in a second region between the tip and an end of the first weight portion 12d on the tip side of the second drive vibrating arm 442 (hereinafter referred to as “the tip of the first weight portion 12d”); , Including.

  The first region is a region having a quadrangular area A1 spaced from the tip of the second drive vibrating arm 442 (tip of the weight portion 446) and both sides of the weight portion 446. The first weight portion 12d is a quadrangle that substantially overlaps the first region, and is provided with a mass B1.

  The second region is a region of area A2 provided in the second region, which is a region between the tip of the first weight portion 12d and the tip of the second drive vibrating arm 442 facing the tip of the first weight portion 12d. It is. The second weight portion 11d is formed in the second region from the substantially central portion in the width direction (x-axis direction) of the first weight portion 12d on the distal end side of the second drive vibration arm 442. The quadrilateral is narrower than the first weight portion 12d reaching the tip and is provided with a mass B2.

  As described above, the weight portion 13 d is formed in a convex shape toward the tip end side of the second drive vibrating arm 442. The weight portion 13d has an area A1 of the first region, an area A2 of the second region, a mass B1 of the first weight portion 12d, and a mass B2 of the second weight portion 11d such that B1 / A1> B2 / A2. Is provided. In this example, the first weight portion 12d and the second weight portion 11d are formed with the same thickness, and in order to satisfy the above relational expression, the first weight portion 12d is provided with substantially the same shape as the first region. The second weight portion 11d is provided so that the width of the second weight portion 11d is narrower than the width of the second region.

  Similarly, the weight portion 447 of the third drive vibrating arm 443 is provided with a weight portion 13a. The weight portion 13a includes a first weight portion 12a provided in a first region of the third drive vibration arm 443 with a space from the tip of the third drive vibration arm 443 toward the base 41 side, and the third drive vibration arm 443. A second weight portion 11a provided in a second region between the tip and an end on the tip side of the third drive vibrating arm 443 of the first weight portion 12a (hereinafter referred to as "the tip of the first weight portion 12a"); , Including.

  The first region is a region having a quadrangular area A1 spaced from the tip of the third drive vibrating arm 443 (tip of the weight portion 447) and both sides of the weight portion 447. The first weight portion 12a is a quadrilateral that substantially overlaps the first region, and is provided with a mass B1.

  The second region is a region having an area A2 provided in the second region, which is a region between the tip of the first weight portion 12a and the tip of the third drive vibrating arm 443 facing the tip of the first weight portion 12a. It is. The second weight portion 11a is located within the second region from the substantially central portion in the width direction (x-axis direction) of the first weight portion 12a on the tip side of the third drive vibration arm 443. The quadrilateral is narrower than the first weight portion 12a reaching the tip, and is provided with a mass B2.

  As described above, the weight portion 13 a is formed in a convex shape toward the tip end side of the third drive vibrating arm 443. The weight portion 13a has an area A1 of the first region, an area A2 of the second region, a mass B1 of the first weight portion 12a, and a mass B2 of the second weight portion 11a such that B1 / A1> B2 / A2. Is provided. In this example, the first weight portion 12a and the second weight portion 11a are formed with the same thickness, and in order to satisfy the above relational expression, the first weight portion 12a is provided with substantially the same shape as the first region. The second weight portion 11a is provided so that the width of the second weight portion 11a is narrower than the width of the second region.

  Similarly, the weight portion 448 of the fourth drive vibrating arm 444 is provided with a weight portion 13b. The weight portion 13b includes a first weight portion 12b provided in a first region of the fourth drive vibration arm 444 with a space from the tip of the fourth drive vibration arm 444 toward the base 41 side, and the fourth drive vibration arm 444. A second weight portion 11b provided in a second region between the tip and an end of the first weight portion 12b on the tip side of the fourth drive vibrating arm 444 (hereinafter referred to as “the tip of the first weight portion 12b”); , Including.

  The first region is a region having a quadrangular area A1 spaced from the tip of the fourth drive vibrating arm 444 (tip of the weight portion 448) and both sides of the weight portion 448. The first weight portion 12b is a quadrangle that substantially overlaps the first region, and is provided with a mass B1.

  The second region is a region having an area A2 provided in the second region, which is a region between the tip of the first weight portion 12b and the tip of the fourth drive vibrating arm 444 facing the tip of the first weight portion 12b. It is. The second weight portion 11b is located in the second region from the substantially central portion in the width direction (x-axis direction) of the first weight portion 12b on the distal end side of the fourth drive vibration arm 444. The quadrilateral is narrower than the first weight portion 12b reaching the tip and is provided with a mass B2.

  As described above, the weight portion 13 b is formed in a convex shape toward the distal end side of the fourth drive vibrating arm 444. The weight portion 13b has an area A1 of the first region, an area A2 of the second region, a mass B1 of the first weight portion 12b, and a mass B2 of the second weight portion 11b such that B1 / A1> B2 / A2. Is provided. In this example, the first weight portion 12b and the second weight portion 11b are formed with the same thickness, and the first weight portion 12b is provided in substantially the same shape as the first region in order to satisfy the above relational expression. The second weight portion 11b is provided so that the width of the second weight portion 11b is narrower than the width of the second region.

  In this example, a weight is provided at the distal end side of the two pairs of drive vibration arms of the first drive vibration arm 441, the second drive vibration arm 442, the third drive vibration arm 443, and the fourth drive vibration arm 444. Although the configuration in which the portions 13a, 13b, 13c, and 13d are provided has been described, the configuration is not limited thereto. For example, it may be configured to be provided on at least one of the first drive vibration arm 441 and the second drive vibration arm 442 and at least one of the third drive vibration arm 443 and the fourth drive vibration arm 444. Good.

  The weight portion 445 of the first drive vibration arm 441, the weight portion 446 of the second drive vibration arm 442, the weight portion 447 of the third drive vibration arm 443, and the weight portion 448 of the fourth drive vibration arm 444 are convex as described above. By providing the weight portions 13c, 13d, 13a, and 13b having a shape, it is possible to suppress the temperature drift of the gyro element 2 caused by the weight portions 13c, 13d, 13a, and 13b being displaced in the y-axis direction. Details will be described later.

  The gyro element 2 having such a configuration detects the angular velocity ω around the z-axis as follows. When an electric field is generated between the drive signal electrode (not shown) and the drive ground electrode (not shown) in a state where the angular velocity ω is not applied, the gyro element 2 is driven as shown in FIG. The vibrating arms 441, 442, 443, and 444 perform bending vibration in the direction indicated by the arrow A. At this time, the first and second drive vibrating arms 441 and 442 and the third and fourth drive vibrating arms 443 and 444 perform plane-symmetric vibration with respect to the yz plane passing through the center point G (center of gravity G). Therefore, the base 41, the first and second connecting arms 431 and 432, and the first and second detection vibrating arms 421 and 422 hardly vibrate.

  When an angular velocity ω is applied around the z-axis to the gyro element 2 in a state where this driving vibration is performed, vibration as shown in FIG. 3B is generated. That is, Coriolis force in the direction of arrow B acts on the drive vibrating arms 441, 442, 443, 444 and the connecting arms 431, 432, and in response to the vibration in the direction of arrow B, the detected vibration in the direction of arrow C is excited. . Then, the detection signal electrode (not shown) and the detection ground electrode (not shown) detect the distortion of the detection vibrating arms 421 and 422 generated by this vibration, and the angular velocity ω is obtained.

(package)
The package 9 stores the gyro element 2. The package 9 may contain an IC chip or the like for driving the gyro element 2 in addition to the gyro element 2 as in an electronic device described later. Such a package 9 has a substantially rectangular shape in plan view (xy plan view).

  The package 9 has a base 91 having a recess opened on the upper surface, and a lid (lid) 92 joined to the base so as to close the opening of the recess. The base 91 has a plate-like bottom plate 911 and a frame-like side wall 912 provided on the peripheral edge of the upper surface of the bottom plate 911. Such a package 9 has a storage space inside, and the gyro element 2 is stored and installed in the storage space in an airtight manner.

  The gyro element 2 has conductive properties such as solder, silver paste, and conductive adhesive (adhesive in which conductive fillers such as metal particles are dispersed in a resin material) at the first and second support portions 51 and 52. It is fixed to the upper surface of the bottom plate 911 via a fixing member 8. Since the first and second support portions 51 and 52 are located at both ends of the gyro element 2 in the y-axis direction, the vibrating body 4 of the gyro element 2 can be held at both ends by fixing such portions to the bottom plate 911. The gyro element 2 is supported and can be stably fixed to the bottom plate 911. Therefore, unnecessary vibration (vibration other than detection vibration) of the gyro element 2 is suppressed, and the detection accuracy of the angular velocity ω by the gyro element 2 is improved.

  The conductive fixing member 8 corresponds to two detection signal terminals 714, two detection ground terminals 724, a drive signal terminal 734, and a drive ground terminal 744 provided in the first and second support portions 51 and 52 ( 6) in contact with each other and spaced apart from each other. Further, six connection pads 10 corresponding to the two detection signal terminals 714, the two detection ground terminals 724, the drive signal terminal 734, and the drive ground terminal 744 are provided on the upper surface of the bottom plate 911, and a conductive fixing member is provided. These connection pads 10 and any one of the corresponding terminals are electrically connected via 8.

(Configuration of weight part)
Next, regarding the weight portions 13c, 13d, 13a, and 13b provided on the first drive vibration arm 441, the second drive vibration arm 442, the third drive vibration arm 443, and the fourth drive vibration arm 444 described above, respectively. The configuration and effect will be described in detail with reference to FIGS. For convenience of explanation, each drawing including the conventional configuration shown in FIG. 4 is described using the third drive vibrating arm 443 and the fourth drive vibrating arm 444 according to the present embodiment. Further, the other first drive vibrating arm 441 and the second drive vibrating arm 442 have the same configuration, and thus the description thereof is omitted.
4A and 4B show the relationship between the conventional weight portion and the temperature drift of the gyro element, where FIG. 4A is a partial plan view showing the form of the weight portion, and FIG. 4B is the amount of deviation of the weight portion and the temperature drift amount. It is a graph which shows correlation with. FIG. 5 shows the relationship between the weight part and the temperature drift of the gyro element in this embodiment, (A) is a partial plan view showing the form of the weight part, and (B) is the deviation amount and temperature of the weight part. It is a graph which shows the correlation with the drift amount. FIG. 6 shows the relationship between the weight part and the temperature drift of the gyro element in this embodiment, (A) is a partial plan view showing the form of the weight part, and (B) is the deviation amount and temperature of the weight part. It is a graph which shows the correlation with the drift amount. FIG. 7 shows the relationship between the weight part and the temperature drift of the gyro element in this embodiment, (A) is a partial plan view showing the form of the weight part, and (B) is the deviation amount and temperature of the weight part. A graph showing the correlation with the drift amount, (C) is an enlarged plan view showing the details of the shape of the weight portion.
Here, the temperature drift amount refers to a frequency change amount of the gyro element with respect to a temperature change.

<Weight part in conventional configuration>
First, the relationship between the conventional weight part and the temperature drift of the gyro element (hereinafter also referred to as temperature drift) will be described with reference to FIG. As shown in FIG. 4A, the weight portion 447 of the third drive vibrating arm 443 is provided with the weight portion 21, and the weight portion 448 of the fourth drive vibrating arm 444 is provided with the weight portion 22. It has been. The weight portion 21 and the weight portion 22 are provided from positions L1 and L3 indicated by a two-dot chain line in the drawing to respective tips 447a and 448a of the weight portions 447 and 448 so that the mass and the position thereof are the same. .

However, if the deposition mask mounting position when forming the weight portion 21 and the weight portion 22 is shifted in the extending direction of the third drive vibration arm 443 and the fourth drive vibration arm 444, the weight portion 21 and The position where the weight portion 22 is formed shifts as shown by hatching in the figure. Since the vapor deposition mask is integrally formed so as to correspond to a large number of weight portions of the large number of gyro elements 2, when the mounting position is shifted, the pair of weight portions 21 and 22 are also shifted by the same amount in the same direction. .
In this example, displacements of displacement amounts M1 and M2 (M1 and M2 are the same amount) occur in the −y-axis direction, and the weight portion 21 has the end on the base side of the third drive vibrating arm 443 at the position L2. In the weight portion 22, the end on the base side of the fourth drive vibrating arm 444 is positioned at L <b> 4.

  Thus, the masses of the weight part 21 and the weight part 22 are changed by shifting the formation positions of the weight part 21 and the weight part 22. As a result, the mass balance between the weight portion 21 and the weight portion 22 formed on the pair of third drive vibration arm 443 and fourth drive vibration arm 444 is lost, and temperature drift occurs in the gyro element 2 due to mass unbalance. Will end up.

Next, the correlation between the amount of deviation between the weight portion 21 and the weight portion 22 and the temperature drift will be described with reference to the graph of FIG.
In the conventional example, the larger the mass unbalance of the weights 21 and 22, in other words, the greater the amount of deviation in the y-axis direction of the deposition mask mounting position, the greater the temperature drift. In the displacement of the evaporation mask as in this example, the weight portion 22 increases as the weight portion 21 decreases. However, if the evaporation mask shifts in the opposite direction, the weight portion 21 gradually increases and the weight portion 22 decreases. . By increasing the mass imbalance in this way, as shown in FIG. 5B, the correlation between the amount of deviation between the weight part 21 and the weight part 22 and the temperature drift is the approximate line W1 having a negative slope. Become.
In particular, the shapes of the weight portion 21 and the weight portion 22 in the conventional example reach the tips 447a and 448a of the respective weight portions 447 and 448, so that when the deposition mask mounting position is shifted in the y-axis direction, The mass of the weight portion 21 becomes smaller and the mass of the other weight portion 22 becomes larger. In such a configuration, since the deviation amount appears as a change in mass directly, it is greatly affected by mass imbalance, and the inclination of the approximate line W1 in the figure becomes large. That is, the displacement of the vapor deposition mask has a great influence on the temperature drift.

<Form 1 of weight part>
Next, the relationship between the weight form 1 and the temperature drift of the gyro element (hereinafter also referred to as temperature drift) will be described with reference to FIGS. 5 and 6. FIG. 5A is a partial plan view showing a state in which the weight portion is displaced within the weight portion, and FIG. 5B is a graph showing the correlation between the displacement amount of the weight portion and the temperature drift amount. FIG. 6A is a partial plan view showing a state in which one weight portion is displaced so as to be out of the weight portion, and FIG. 6B is a graph showing the correlation between the displacement amount of the weight portion and the temperature drift amount. It is.

As shown in FIG. 5A, the weight portion 447 of the third drive vibrating arm 443 is provided with the weight portion 25, and the weight portion 448 of the fourth drive vibrating arm 444 is provided with the weight portion 26. It has been. In the figure, the weight part 25 and the weight part 26 are disposed inside the weight parts 447 and 448 (with a space between each of the front ends 447a and 448a and both sides) so that the mass and the position are originally the same. It is provided like rectangular shapes 25a and 26a indicated by two-dot chain lines.
However, when the mounting positions of the vapor deposition masks forming the weight portions 25 and 26 are shifted in the −y-axis direction by the shift amounts M1 and M2, the weight portion 25 and the weight portion 26 are inside the weight portions 447 and 448 (in a plane). In other words, the weight part 25 and the weight part 26 are formed so as not to be separated from the weight parts 447 and 448. In this case, the weight portion 25 and the weight portion 26 are formed at the positions shown by hatching in the drawing, and the displacements M1 and M2 (M1 and M2 are the same amount) are displaced in the −y axis direction. In the weight portion 25, the end on the base side of the third drive vibrating arm 443 is in the position from L1 to L2, and in the weight portion 26, the end on the tip 448a side of the fourth drive vibrating arm 444 is in the position from L3 to L4.

Since the vapor deposition mask is integrally formed so as to correspond to the weight portions 25 and 26 of the many gyro elements 2, if the mounting position is shifted, the pair of weight portions 25 and 26 are also shifted in the same direction by the same amount. Become. Therefore, the center of gravity P1 of the weight part 25 moves to the center of gravity P2, and the center of gravity P3 of the weight part 26 moves to the center of gravity P4.
As described above, when the formation positions of the weight part 25 and the weight part 26 are shifted inside the weight parts 447 and 448, the mass balance between the weight part 25 and the weight part 26 does not change, and the position (center of gravity) balance does not change. Will change.

However, the weight portions 25 and 26 have a greater influence on the temperature drift as the positions thereof are closer to the tips 447a and 448a of the third drive vibration arm 443 and the fourth drive vibration arm 444. As a result, the weight portion 25 whose center of gravity has moved to the tip 447a side is in a state in which the mass is increased in a pseudo manner, and the weight portion 26 in which the center of gravity is moved to the base side is in a state in which the mass is reduced in a pseudo manner.
Accordingly, if the formation position of the weight portion 25 and the weight portion 26 is deviated inside the weight portions 447 and 448, the degree of influence on temperature drift is smaller than the degree of influence due to mass variation of the conventional example. can do.

  In addition, in order to reduce the influence on the temperature drift due to the change of the center of gravity balance in the formation position of the weight part 25 and the weight part 26, the distance between the tip parts 447a and 448a of the weight parts 447 and 448 and the weight parts 25 and 26 is set. It is desirable that the size is greater than or equal to the y-axis direction dimension of the weight portions 25 and 26. This is effective in reducing the degree of influence due to mass variation caused by the weight portions 25 and 26 approaching the tips 447a and 448a of the weight portions 447 and 448.

Such a correlation between the amount of deviation between the weight portion 25 and the weight portion 26 inside the weight portions 447 and 448 and the temperature drift will be described with reference to the graph of FIG.
In the above-described embodiment, the weight portions 25 and 26 are displaced in the −y axis direction. The weight portion 25 is displaced toward the tip end 447 a of the weight portion 447, and the weight portion 26 is displaced toward the base side of the fourth drive vibrating arm 444. As described above, since the weight portion 25 shifted to the tip 447a side of the weight portion 447 is in a state where the mass is increased in a pseudo manner, the change in mass is reversed as compared with the case of the conventional example described above. Therefore, as shown in FIG. 5B, the slope of the approximate line PU1 is a positive slope (the slope opposite to that of the conventional example). Further, since the mass change does not occur directly, the inclination (absolute value) can be reduced. In other words, the degree of influence on temperature drift can be reduced.

Next, the case where the formation of the weight portion of the first embodiment described with reference to FIG. 5 is further shifted to the outside of the weight portions 447 and 448 will be described with reference to FIG. In the description here, the description overlapping with the description using FIG. 5 is omitted.
As shown in FIG. 6A, the weight portion 25 is formed in a state where it is detached from the tip 447a of the weight portion 447. In this case, the weight portion 25 and the weight portion 26 are displaced in the −y-axis direction from the positions of the rectangular shapes 25a and 26a indicated by the two-dot chain lines in the drawing, which are the original positions, M3 and M4 (M3 and M4 are the same amount). ). In the weight portion 25, the base side end of the third drive vibrating arm 443 is located at a position from L1 to L5, and the tip portion 447a side of the weight portion 447 is located at a position 25a ′ (indicated by a two-dot chain line) that is out of the weight portion 447. . That is, a part of the weight part 25 on the tip 447a side is not formed, and the surface area of the weight part 25 is reduced. In the weight portion 26, the end of the fourth drive vibrating arm 444 on the front end 448a side is positioned from L3 to L6. Further, the center of gravity P1 of the weight part 25 moves to the center of gravity P5, and the center of gravity P3 of the weight part 26 moves to the center of gravity P6.
As described above, when the weight portion 25 is disengaged from the tip 447a of the weight portion 447, the influence on the temperature drift due to the mass unbalance of the mass change described in the conventional example is taken into consideration. The description will be made with reference to FIG. Here, the case where the weight portion 25 is disengaged from the tip 447a of the weight portion 447 will be described.
When the weight part 25 is inside the weight part 447, the influence is along the approximate line PU1 having a positive slope as described above, but the place where the weight part 25 starts outside the weight part 447. As an inflection point, a correlation with mass imbalance due to mass change is added. In other words, in the region on the left side from the inflection point, that is, when the weight portion 25 protrudes outside the weight portion 447, an approximation having a negative slope that is a correlation between mass imbalance due to mass change and temperature drift. This is a correlation between an approximate line (W2 + PU1) having an inclination obtained by adding the line W2 and an approximate line PU1 having a positive inclination that is a correlation between a position imbalance due to a change in position (center of gravity) balance and temperature drift.

  Thus, in the form of the weight parts 25 and 26 of the form 1, when the displacement of the deposition mask mounting position occurs, the occurrence of temperature drift due to the displacement of the weight parts 25 and 26 can be suppressed. That is, the correlation between the displacement of the weight portions 25 and 26 and the temperature drift can be reduced.

<Form 2 of the weight part>
Next, the relationship between the weight part form 2 and the temperature drift will be described with reference to FIG. FIG. 7A is a partial plan view showing a state in which the weight portion is displaced within the weight portion, and FIG. 7B is a graph showing the correlation between the displacement amount of the weight portion and the temperature drift amount, FIG. 4C is an enlarged plan view showing details of the shape of the weight portion.

  The weight portions 13a and 13b of the present embodiment are formed with the configuration described in detail in the section of (weight portion of gyro element) of the above-described embodiment. In brief, the weight parts 13a and 13b are formed to include first weight parts 12a and 12b and second weight parts 11a and 11b having a smaller mass per unit area than the first weight parts 12a and 12b. . In this description, the description will be given using the weight portion 13b provided in the fourth drive vibrating arm 444. Further, the first region means all regions where the first weight portion 12b is provided. The boundary line between the first region and the second region is a boundary where the shape, mass, material, thickness, etc. of the weight portion 13b change, and the tip of the first weight portion 12b (fourth). This is the side of the driving vibration arm 444 on the tip side.

  The weight portion 13b includes a first weight portion 12b provided in a first region of the fourth drive vibration arm 444 with a space from the tip of the fourth drive vibration arm 444 toward the base 41 side, and the fourth drive vibration arm 444. And a second weight portion 11b provided in a second region between the tip and the tip of the first weight portion 12b.

  As described above, the first region is a region having an area A1, and the first weight portion 12b is a quadrangle substantially overlapping the first region, and is provided with a mass B1. The second region is a region having an area A2, and the second weight portion 11b is a quadrilateral having a smaller width than the first weight portion 12b and having a mass B2 in the second region. Yes. That is, the weight portion 13 b is formed in a convex shape toward the distal end side of the fourth drive vibrating arm 444.

  The weight portion 13b has an area A1 of the first region, an area A2 of the second region, a mass B1 of the first weight portion 12b, and a mass B2 of the second weight portion 11b such that B1 / A1> B2 / A2. Is provided. In this example, the first weight portion 12b and the second weight portion 11b are formed with the same thickness, and the first weight portion 12b is provided in substantially the same shape as the first region in order to satisfy the above relational expression. The second weight portion 11b is provided so that the width of the second weight portion 11b is narrower than the width of the second region.

Originally, it is desirable that the weight parts 13a and 13b are provided so as to be symmetrical and have the same mass and position as the weight parts 13a 'and 13b' shown by two-dot chain lines in the drawing. However, when the mounting positions of the vapor deposition masks forming the weight portions 13a and 13b are shifted in the −y axis direction by the shift amounts M5 and M6 as in the first embodiment, the weight portion 13a and the weight portion 13b are the weight portions 447, It shifts inside 448 (within the plane area). FIG. 5A shows a case where the weight part 13a and the weight part 13b are displaced to the extent that they do not come off the weight parts 447 and 448. In this case, the weight part 13a and the weight part 13b are formed at the positions indicated by hatching in the drawing, and the positional deviations of the deviation amounts M5 and M6 (M5 and M6 are the same quantity) occur in the −y-axis direction.
The weight portion 13a has a base side end of the third drive vibrating arm 443 at a position L2 shifted from the original position L1 by a shift amount M5, and the weight portion 13b is a base side end of the fourth drive vibration arm 444. Is the position of L4 which is shifted from the original position L3 by the shift amount M6.

  Since the vapor deposition mask is integrally formed so as to correspond to the weight portions 13a and 13b of the large number of gyro elements 2, if the mounting position is shifted, the pair of weight portions 13a and 13b are also shifted in the same direction by the same amount. Become. The center of gravity P1 of the weight part 13a moves to the center of gravity P2, and the center of gravity P3 of the weight part 26 moves to the center of gravity P4. When the deposition mask is greatly displaced in the −y-axis direction, only the first weight portion 12a is formed in the weight portion 447, and the first weight portion 12b and the second weight portion 11b are formed in the weight portion 448. Will be.

As described above, when the formation positions of the weight part 13a and the weight part 13b are shifted inside (in-plane) the weight parts 447 and 448, the weight part 13a and the weight part 13b have their mass balance and position (center of gravity). The balance will change.
By changing the position (center of gravity) balance, the first weight portion 12a whose center of gravity has moved to the tip 447a side has a pseudo-mass increased state, and the first weight portion 12b whose center of gravity has moved to the base side has been simulated. The mass is reduced. In the second embodiment, the second mass portions 11a and 11b having a smaller mass per unit area than the first mass portions 12a and 12b cancel out the pseudo mass imbalance and reduce the influence on the temperature drift. I am letting.

Reducing the influence on the temperature drift with the structure of Embodiment 2 will be described with reference to FIGS. 7B and 7C. In addition, in the figure (C), it demonstrates using the weight part 13b as a representative.
The weight portion 13b of the form 2 has a first weight portion 12b formed in a rectangular shape having a width S × length T and a second weight portion 11b formed in a rectangular shape having a width S / 3 × length 2T. doing.

  The first weight portion 12b is provided in the plane of the weight portion 448 (a first region indicated by right-down cross hatching in the drawing) with a gap from the tip 448a of the fourth drive vibrating arm 444 to the base 41 side. The second weight portion 11b is provided in a second region that is a region between the tip 448a of the fourth drive vibrating arm 444 and the tip of the first weight portion 12b. Note that the second region is a region in which the width in the x-axis direction of the tip of the first weight portion 12b is directly extended to the tip 448a of the fourth drive vibrating arm 444, and is a region indicated by a broken line (dotted line) in the drawing. . Here, since the second weight portion 11b is provided with a width (S / 3) that is 1/3 of the width S of the second region, the second weight portion 11b has a width S × length T of approximately the same area as the first region. Compared to the first weight portion 12b formed in a shape, the mass per unit area is reduced. That is, in the weight portion 13b, the area A1 of the first region, the area A2 of the second region, the mass B1 of the first weight portion 12b, and the mass B2 of the second weight portion 11b satisfy B1 / A1> B2 / A2. It is provided as follows.

  In the configuration of the weight layer form 2 as described above, when the formation position of the weight portion 13b is shifted in the −y-axis direction, the second weight portion 11b provided near the tip 448a is The first weight portion 12b provided at a position distant from the tip 448a becomes a correlation between the weight unbalance and the temperature drift.

Since the mass per unit area of the second weight part 11b located near the tip 448a is configured to be smaller in the weight part 13b of the form 2, the degree of influence on the mass unbalance and temperature drift of the weight is greater than that of the form 1. Can be further reduced. In other words, the slope of the approximate line W3 shown in FIG. 7B, which shows the mass imbalance of the weight and the degree of influence on the temperature drift, can be made smaller than the slope of the approximate line W2 shown in FIG.
Further, the first weight portion 12b is correlated with the position imbalance of the weight, but is provided at a position (at a distance) away from the tip 448a where the second weight portion 11b is provided. The influence on the position imbalance and temperature drift of the weight can be further reduced as compared with the first embodiment. That is, the slope of the approximate line PU2 indicating the degree of influence on the position imbalance and temperature drift of the weight shown in FIG. 7B can be made smaller than the slope of the approximate line PU1 shown in FIG.

  The inclination of the approximate line W3 indicating the influence on the mass unbalance and the temperature drift of the weight and the inclination of the approximate line PU2 indicating the influence on the position imbalance and the temperature drift of the weight are substantially equal to each other. , Each influence is negated. By adding these two approximate lines W3 and PU2, it is possible to obtain an approximate line W3 + PU2 having almost no influence on the temperature drift. That is, by using the weight part 13b having the first weight part 12b and the second weight part 11b, even when the formation position of the weight part 13b is shifted in the -y-axis direction due to the displacement of the deposition mask mounting position or the like, Almost no influence on temperature drift can be generated.

  Further, as described above, the width of the second weight portion 11b is set to 1/3 of the width of the first weight portion 12b, and the mass per unit area of the second weight portion 11b is determined per unit area of the first weight portion 12b. By making it smaller than the mass, the absolute value of the slope of the approximate line W3 and the slope of the approximate line PU2 can be made substantially equal, and a simulation result is also obtained in which an approximate line overlapping the substantially horizontal axis is obtained. Yes.

  Further, as shown in FIG. 7A, the second weight portion 11b provided in the fourth drive vibrating arm 444 has a mass greater than that of the second weight portion 11a provided in the third drive vibrating arm 443. large. Thereby, the influence of the temperature drift due to the position imbalance of the first weight parts 12a and 12b and the influence of the temperature drift due to the mass imbalance of the second weight parts 11a and 11b are offset, and the temperature drift is reduced as a whole.

(Deformation example of weight part)
In the above-described weight portions 13a and 13b, the example of the convex shape is shown and described. However, if the mass per unit area of the second weight portion is smaller than the mass per unit area of the first weight portion, the same effect is obtained. Will have. FIG. 8 shows and describes a typical modification of the weight portion. 8A to 8E are enlarged plan views showing details of the shape of the weight portion in the modification. In this description, the description will be made using a portion corresponding to the weight portion 13b provided in the fourth drive vibrating arm 444, but the present invention can also be applied to other weight portions. Further, the first region means all regions where the first weight portion 12b is provided. The boundary line between the first region and the second region is a boundary where the shape, mass, material, thickness, etc. of the weight portion 13b change, and the tip of the first weight portion 12b (fourth). This is the side of the driving vibration arm 444 on the tip side.

  The weight part 13e of the modification shown in FIG. 8A includes a first weight part 12e and a second weight part 11e having a smaller mass per unit area than the first weight part 12e, and is formed in the weight part 448. Yes. The first weight portion 12e is provided in a rectangular shape at a position spaced from the tip of the weight portion 448. The second weight portion 11e is provided between the front end of the weight portion 448 and the first weight portion 12e, and is provided in a rectangular shape on the front end side of the weight portion 448. The second weight portion 11e has a reduced mass by reducing the width direction (x-axis direction in the embodiment) dimension of the weight portion 448. Note that a boundary line L10 in the figure indicates the boundary between the first region and the second region.

  The weight portion 13f of the modified example shown in FIG. 8B includes a first weight portion 12f and a second weight portion 11f having a smaller mass per unit area than the first weight portion 12f, and is formed in the weight portion 448. Yes. The first weight portion 12f is provided in a rectangular shape at a position spaced from the tip of the weight portion 448. The second weight portion 11f is between the tip of the weight portion 448 and the first weight portion 12f, and extends from both ends of the first weight portion 12f in the width direction (x-axis direction in the embodiment) toward the tip of the weight portion 448. It has two protruding third weight portions 11f ′ and 11f ″. The second weight portion 11f is provided so that the width direction (x-axis direction in the embodiment) dimension of the weight portion 448 is reduced when the two third weight portions 11f ′ and 11f ″ are added. The mass is reduced. Note that a boundary line L10 in the figure indicates the boundary between the first region and the second region.

  The weight part 13h of the modification shown in FIG. 8C includes a first weight part 12h and a second weight part 11h having a smaller mass per unit area than the first weight part 12h, and is formed in the weight part 448. Yes. The first weight portion 12h is provided in a rectangular shape at a position spaced from the tip of the weight portion 448. The second weight portion 11h is provided between the tip of the weight portion 448 and the first weight portion 12h, extends from the first weight portion 12h, and has a shape whose width decreases toward the tip of the weight portion 448. Yes. Note that the second weight portion 11h has a smaller mass by reducing the width direction (x-axis direction in the embodiment) dimension of the weight portion 448. Note that a boundary line L10 in the figure indicates the boundary between the first region and the second region.

  The weight portion 13k of the modification shown in FIG. 8D includes a first weight portion 12k and a second weight portion 11k having a smaller mass per unit area than the first weight portion 12k, and is formed in the weight portion 448. Yes. The first weight portion 12k is provided in a rectangular shape at a position spaced from the tip of the weight portion 448. The second weight portion 11k is between the tip of the weight portion 448 and the first weight portion 12k, has a slight gap with the first weight portion 12k, and has a narrow rectangular shape extending toward the tip of the weight portion 448. The third weight portions 11k ′, 11k ″, 11k ′ ″. The second weight portion 11k has a smaller size in the width direction (x-axis direction in the embodiment) of the weight portion 448 when the three third weight portions 11k ′, 11k ″, 11k ′ ″ are added. Thus, the mass is reduced. Note that a boundary line L10 in the figure indicates the boundary between the first region and the second region.

  The weight part 13m of the modified example shown in FIG. 8E includes a first weight part 12m and a second weight part 11m having a smaller mass per unit area than the first weight part 12m, and is formed in the weight part 448. Yes. The first weight portion 12m is provided in a rectangular shape at a position spaced from the tip of the weight portion 448. The second weight portion 11m is between the tip of the weight portion 448 and the first weight portion 12m, and extends from both ends of the first weight portion 12m in the width direction (x-axis direction in the embodiment) toward the tip of the weight portion 448. The inner side has two protruding portions (third weight portions) 11m ′ and 11m ″ protruding in a round shape. Note that the second weight portion 11m has a reduced width direction (x-axis direction in the embodiment) dimension of the weight portion 448 when two projecting portions (third weight portions) 11m ′ and 11m ″ are added. The mass is reduced by providing it in Thus, the structure which has a curve in the external shape of the weight part 13m may be sufficient. Note that a boundary line L10 in the figure indicates the boundary between the first region and the second region.

  In the above-described modification, some examples in which the second weight part is divided into a plurality of parts have been described. However, in contrast to this configuration, the first weight part may be divided into a plurality of parts. .

Moreover, since the mass per unit area should just be smaller in the 2nd weight part than the 1st weight part, the following structures may be sufficient, for example.
(1) A second weight portion formed with the same thickness as the first weight portion and having a width dimension in the x-axis direction narrower than that of the first weight portion.
(2) As shown in FIG. 9A, the second weight part 11n (shown by hatching) is formed with the same thickness and width as the first weight part 12n and is made of a material having a lighter specific gravity than the first weight part 12n. portion).
(3) As shown in FIG. 9B, a second weight part 11r that is formed in the same shape as the first weight part 12r and is thinner than the first weight part 12r.
(4) As shown in FIG. 9C, a second weight portion 11s formed in a mesh (net-like shape) in the same shape as the first weight portion 12s.

  The weight portion having the configuration described in the above-described modification also has the same effect as the weight portion having the configuration shown in the embodiment (form of the weight portion).

(Gyro element manufacturing method)
Next, a method for manufacturing a gyro element according to the present invention will be described with reference to the drawings. FIG. 10 is a flowchart showing a schematic manufacturing process of the gyro element 2 as the vibrating piece shown in FIG. 2 described above.

  First, a substrate such as a quartz plate is prepared. Then, the first, second, third, and fourth drive vibrating arms 441, 442, 443, 444, and the first and second detection vibrating arms shown in FIG. External shapes such as 421 and 422 are formed to form a gyro element base plate (step S102).

  Next, an electrode film is formed on the surface of the gyro element base plate (step S104). The electrode film has a configuration in which, for example, a base metal layer such as chromium (Cr) is formed in order to improve adhesion to quartz, and a gold (Au) layer is formed on the surface thereof. The electrode film can be formed by vapor deposition or sputtering.

Next, the detection arm weight layers 14 and 15 are formed on the weight portions 425 and 426 at the distal ends of the first and second detection vibrating arms 421 and 422 shown in FIG. 2, and the first, second, third, and second The weight portions 13a, 13b, 13c, and 13d are formed on the weight portions 445, 446, 447, and 448 at the tip portions of the four-drive vibrating arms 441, 442, 443, and 444 (step S106).
Here, the weight parts 13a, 13b, 13c, and 13d are the first weight parts 12a provided at intervals from the tips of the first, second, third, and fourth drive vibrating arms 441, 442, 443, and 444, respectively. , 12b, 12c, 12d and the first, second, third, and fourth drive vibrating arms 441, 442, 443, 444 and the first weight portions 12a, 12b, 12c, 12d. In addition, it includes second weight parts 11a, 11b, 11c, and 11d that have a smaller mass per unit area than the first weight parts 12a, 12b, 12c, and 12d.
Note that the step of forming the first weight portions 12a, 12b, 12c, and 12d and the step of forming the second weight portions 11a, 11b, 11c, and 11d can be performed in different steps. As described above, the first weight parts 12a, 12b, 12c, and 12d and the second weight parts 11a, 11b, 11c, and 11d are formed in different steps, thereby providing the first weight parts 12a, 12b, and 12c. , 12d and the second weight portions 11a, 11b, 11c, and 11d, for example, can correspond to changing the material, changing the thickness, or making one of them meshed.
The detection arm weight layers 14, 15 and the weight portions 13a, 13b, 13c, 13d are formed by forming a metal layer such as gold (Au) by, for example, vapor deposition or sputtering using a metal mask. Is formed thicker than the electrode film.

  Next, mass adjustment of the first and second detection vibrating arms 421 and 422 is performed, and the natural resonance frequencies of the first and second detection vibrating arms 421 and 422 are adjusted to a desired frequency (step S108). This mass adjustment is performed to adjust the detuning frequency. For example, the detection arm weight layer formed on the first and second detection vibrating arms 421 and 422 by irradiating the focused laser beam. 14 and 15 are performed by melting and evaporating and removing at least a part of them. If necessary, the electrode film may be removed by melting and evaporation. Further, the mass of the detection arm weight layers 14 and 15 may be added.

Next, mass adjustment of the first, second, third, and fourth drive vibrating arms 441, 442, 443, 444 is performed, and the first, second, third, and fourth drive vibrating arms 441, 442, 443, The vibration arm frequency adjustment for adjusting the natural resonance frequency of 444 to a desired frequency is performed (step S110). In this mass adjustment, the bending vibrations of the first, second, third, and fourth drive vibrating arms 441, 442, 443, and 444 pass through the first connecting arm 431 and the second connecting arm 432, and the first and second detected vibrations. It also has the purpose of preventing so-called vibration leakage that propagates to the arms 421 and 422.
The vibration arm frequency adjustment is performed by changing the natural resonance frequency of each of the first, second, third, and fourth driving vibration arms 441, 442, 443, and 444, and changing the first, second, third, and fourth vibration arms. The drive vibrating arms 441, 442, 443, and 444 are adjusted so as to match the natural resonance frequencies. The vibration arm frequency adjustment (mass adjustment) is performed by, for example, irradiating a focused laser beam to thereby form weights formed on the first, second, third, and fourth drive vibration arms 441, 442, 443, and 444. This is done by melting and evaporating the parts 13a, 13b, 13c, 13d and the electrodes and removing at least a part thereof. Moreover, the mass of the weight parts 13a, 13b, 13c, and 13d may be added.
The vibration arm frequency adjustment is performed by so-called rough adjustment in which the natural resonance frequency is roughly adjusted, and so-called fine adjustment in which the natural resonance frequency is adjusted by fine mass adjustment.
Further, the vibrating arm frequency adjustment removes at least one of the first weight parts 12a, 12b, 12c, 12d and the second weight parts 11a, 11b, 11c, 11d constituting the weight parts 13a, 13b, 13c, 13d. Can be done. Further, the mass of at least one of the first weight parts 12a, 12b, 12c, 12d and the second weight parts 11a, 11b, 11c, 11d constituting the weight parts 13a, 13b, 13c, 13d may be added.

  Next, the gyro element 2 is completed by inspecting the electrical characteristics of the gyro element 2 and selecting the gyro elements 2 having the desired characteristics (step S112).

  According to the above-described method for manufacturing the gyro element 2 as the resonator element, the detection arm weight layers 14 and 15 and the weight portions 13a, 13b, 13c, and 13d can be formed in the same process. Further, since the first weight parts 12a, 12b, 12c and 12d and the second weight parts 11a, 11b, 11c and 11d constituting the weight parts 13a, 13b, 13c and 13d can be formed in the same process, the gyro element 2 can be efficiently formed. Can be manufactured.

  In the above description, a gyro sensor using a so-called double T-type gyro element as an example has been described. However, the element according to the present invention is not limited to a double T-type gyro element, and extends from the base in opposite directions. Any element having a vibrating arm can be applied. Examples of the element according to the present invention include a so-called H-type gyro element and a vibration element having a tuning fork vibrating arm extending in the opposite direction from the base.

[Electronic device]
Next, a gyro sensor as an example of an electronic device using the above-described gyro element 2 will be described with reference to FIG. FIG. 11 is a front sectional view showing an outline of the gyro sensor.

The gyro sensor 80 includes the gyro element 2 as a vibration piece, an IC 84 as a circuit element, a container 81 as a package, and a lid 86. An IC 84 is disposed on the bottom surface of the container 81 made of ceramic or the like, and is electrically connected to a wiring (not shown) formed in the container 81 by a wire 85 such as Au. The IC 84 includes a drive circuit for driving and vibrating the gyro element 2 and a detection circuit for detecting a detection vibration generated in the gyro element 2 when an angular velocity is applied.
In the gyro element 2, support portions 51 and 52 of the gyro element 2 are bonded and supported on a support base 82 formed in the container 81 via a fixing member 83 such as a conductive adhesive. In addition, a wiring (not shown) is formed on the surface of the support base 82, and conduction between the electrode of the gyro element 2 and the wiring is made through a fixing member 83. The fixing member 83 is preferably made of an elastic material. As the fixing member 83 having elasticity, a conductive adhesive based on silicone is known. The inside of the container 81 is held in a vacuum atmosphere, and the upper opening of the container 81 is sealed with a lid 86.

  In the gyro element 2, the weight portions 13a, 13b, 13c, and 13d provided on the first, second, third, and fourth drive vibrating arms 441, 442, 443, and 444 are replaced by the first weight portions 12a, 12b, 12c and 12d and the second weight portions 11a, 11b, 11c, and 11d are formed so that the temperature drift of the gyro element 2 can be reduced. Therefore, the gyro sensor 80 using the gyro element 2 also has stable characteristics with reduced temperature drift.

[Electronics]
Next, with respect to an electronic apparatus to which the gyro element 2 as a vibrating piece, the vibrator 1 using the gyro element 2 as a vibrating piece, or the gyro sensor 80 as an electronic device according to an embodiment of the present invention is applied. This will be described in detail with reference to FIG. In the description, an example in which the vibrator 1 using the gyro element 2 as a vibrating piece is used is shown.

  FIG. 12 is a perspective view schematically illustrating a configuration of a mobile (or notebook) personal computer as an electronic apparatus including the vibrator 1 according to the embodiment of the invention. In this figure, a personal computer 1100 includes a main body portion 1104 provided with a keyboard 1102 and a display unit 1106 provided with a display portion 100. The display unit 1106 is rotated with respect to the main body portion 1104 via a hinge structure portion. It is supported movably. Such a personal computer 1100 has a built-in vibrator 1 using a gyro element 2 having a function of detecting angular velocity.

  FIG. 13 is a perspective view schematically illustrating a configuration of a mobile phone (including PHS) as an electronic apparatus including the vibrator 1 according to the embodiment of the invention. In this figure, a cellular phone 1200 includes a plurality of operation buttons 1202, an earpiece 1204, and a mouthpiece 1206, and the display unit 100 is disposed between the operation buttons 1202 and the earpiece 1204. Such a cellular phone 1200 incorporates a vibrator 1 using a gyro element 2 that functions as an angular velocity sensor or the like.

FIG. 14 is a perspective view schematically illustrating a configuration of a digital still camera as an electronic apparatus including the vibrator 1 according to the embodiment of the invention. In this figure, connection with an external device is also simply shown. Here, an ordinary camera sensitizes a silver halide photographic film with a light image of a subject, whereas a digital still camera 1300 photoelectrically converts a light image of a subject with an image sensor such as a CCD (Charge Coupled Device). An imaging signal (image signal) is generated.
A display unit 100 is provided on the back of a case (body) 1302 in the digital still camera 1300, and is configured to display based on an imaging signal from the CCD. The display unit 100 displays an object as an electronic image. Functions as a viewfinder. A light receiving unit 1304 including an optical lens (imaging optical system), a CCD, and the like is provided on the front side (the back side in the drawing) of the case 1302.
When the photographer confirms the subject image displayed on the display unit 100 and presses the shutter button 1306, the CCD image pickup signal at that time is transferred and stored in the memory 1308. In the digital still camera 1300, a video signal output terminal 1312 and an input / output terminal 1314 for data communication are provided on the side surface of the case 1302. As shown in the figure, a television monitor 1430 is connected to the video signal output terminal 1312 and a personal computer 1440 is connected to the input / output terminal 1314 for data communication as necessary. Further, the imaging signal stored in the memory 1308 is output to the television monitor 1430 or the personal computer 1440 by a predetermined operation. Such a digital still camera 1300 incorporates a vibrator 1 using a gyro element 2 that functions as an angular velocity sensor or the like.

  The vibrator 1 according to the embodiment of the present invention includes, for example, an ink jet type ejection device in addition to the personal computer (mobile personal computer) in FIG. 12, the mobile phone in FIG. 13, and the digital still camera in FIG. (For example, inkjet printers), laptop personal computers, televisions, video cameras, video tape recorders, car navigation devices, pagers, electronic notebooks (including those with communication functions), electronic dictionaries, calculators, electronic game devices, word processors, workstations , Video phone, crime prevention TV monitor, electronic binoculars, POS terminal, medical equipment (eg, electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish detector, various measuring devices , Instruments (eg, vehicles, aviation , Gauges of a ship), can be applied to electronic equipment such as a flight simulator.

[Moving object]
FIG. 15 is a perspective view schematically showing an automobile as an example of a moving body. The automobile 106 is equipped with the vibrator 1 using the gyro element 2 according to the present invention. For example, as shown in the figure, an automobile 106 as a moving body includes an electronic control unit 108 that includes a vibrator 1 using a gyro element 2 and controls a tire 109 and the like. The vibrator 1 also includes keyless entry, immobilizer, car navigation system, car air conditioner, anti-lock brake system (ABS), air bag, tire pressure monitoring system (TPMS), engine The present invention can be widely applied to electronic control units (ECUs) such as controls, battery monitors for hybrid vehicles and electric vehicles, and vehicle body attitude control systems.

  DESCRIPTION OF SYMBOLS 1 ... Vibrator 2 ... Gyro element as vibrating piece, 4 ... Vibrating body, 8 ... Conductive fixing member (silver paste), 9 ... Package, 10 ... Connection pad, 11a, 11b, 11c, 11d ... 2nd weight Part, 12a, 12b, 12c, 12d ... first weight part, 13a, 13b, 13c, 13d ... weight part, 14, 15 ... detection arm weight layer, 25, 26 ... weight part, 41 ... base part, 51 ... first Support part, 51a ... Joint part, 51b ... Joint part, 52 ... Second support part, 52a ... Joint part, 52b ... Joint part, 61 ... First beam, 62 ... Second beam, 63 ... Third beam, 64 ... 4th beam, 91 ... base, 92 ... lid, 106 ... automobile as moving body, 421 ... 1st detection vibration arm, 422 ... 2nd detection vibration arm, 425, 426, 445, 446, 447, 448 ... wide part As a weight part (hammer head), 431 ... 1st connection 432 ... 2nd connecting arm, 441 ... 1st drive vibration arm, 442 ... 2nd drive vibration arm, 443 ... 3rd drive vibration arm, 444 ... 4th drive vibration arm, 447a, 448a ... Tip of weight part, 714 ... Detection signal terminal as a fixed part, 724... Detection ground terminal as a fixed part, 734... Drive signal terminal as a fixed part, 744... Drive signal terminal as a fixed part, 911 ... Bottom plate, 912. ... adjusting electrode (metal layer), 1100 ... mobile personal computer as electronic equipment, 1200 ... mobile phone as electronic equipment, 1300 ... digital still camera as electronic equipment.

Claims (6)

base,
Forming a first vibrating arm extending from the base in a first direction, and a second vibrating arm extending from the base in a second direction opposite to the first direction. When,
In the range from the tip of the first vibrating arm to the position of the greater second distance greater than the first distance from the position of the first distance, the first with a width direction perpendicular to the first direction in the range A first weight portion having a width smaller than the width of the vibrating arm;
A second weight portion having a width smaller than the width of the first weight portion in the width direction in a range from the position of the tip of the first vibrating arm to a position of a third distance smaller than the first distance;
In the range from the tip of the second vibrating arm to the position of the fourth distance fifth distance greater than the fourth distance from the position of the smaller than the width of the second vibrating arms in the range, and the first weight A third weight part having the same width as the width of the part, and a position of a sixth distance smaller than the fourth distance from the position of the tip of the second vibrating arm, and the second weight part in the width direction. A step of forming a fourth weight portion having the same width as the width by a vapor deposition method or a sputtering method through a mask,
The length of the first weight part that is the difference between the first distance and the second distance is equal to the length of the third weight part that is the difference between the fourth distance and the fifth distance,
The difference between the first distance and the third distance is equal to the difference between the fourth distance and the sixth distance;
The difference between the first distance and the fourth distance is equal to the difference between the third distance and the sixth distance;
A region where the first weight portion is provided is a first region, and a region from the tip of the first vibrating arm to the position of the first distance with a width on the tip side of the first weight portion is a second region,
The area of the first region is A1, the mass of the first weight part is B1,
When the area of the second region is A2, and the mass of the second weight portion is B2,
B1 / A1> B2 / A2,
The region where the third weight portion is provided is the third region, the region from the tip of the second vibrating arm to the position of the fourth distance with the width on the tip side of the third weight portion is the fourth region,
The area of the third region is A3, the mass of the third weight part is B3,
When the area of the fourth region is A4 and the mass of the fourth weight portion is B4,
B3 / A3> B4 / A4.
A method for manufacturing a resonator element, comprising: In the manufacturing method of the vibration piece according to claim 1,
At least one part of at least one of the first weight part and the second weight part is removed, or mass is added to at least one of the first weight part and the second weight part, and the first vibrating arm Adjusting the resonance frequency of
A method of manufacturing a resonator element comprising: In the manufacturing method of the resonator element according to claim 1 or 2,
The second weight portion is provided at a substantially central portion in the width direction of the first vibrating arm,
The method for manufacturing a resonator element, wherein the fourth weight portion is provided at a substantially central portion in the width direction of the second vibrating arm. In the method of manufacturing a resonator element according to any one of claims 1 to 3,
The first weight portion is provided with a space between a side end of the first vibrating arm along the first direction,
The third weight portion is provided with a space between the second vibrating arm and a side end along the first direction of the second vibrating arm. In the production how the resonator element according to any one of claims 1 to 4,
The first vibrating arm includes a first wide portion having a width wider than a width on a base side from the tip to a position at a predetermined distance in plan view,
The second vibrating arm includes a second wide portion having a width wider than the width on the base side from the tip to a position at a predetermined distance in plan view,
The first weight part and the second weight part are provided in the first wide part,
The method for manufacturing a resonator element, wherein the third weight portion and the fourth weight portion are provided in the second wide portion. In the method of manufacturing a resonator element according to any one of claims 1 to 5,
A method for manufacturing a resonator element, comprising: a pair of vibrating arms for detection extending in opposite directions from the base portion.

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