JP6115205B2 - Bending vibration piece, method for manufacturing bending vibration piece, vibration device, electronic apparatus, and moving body - Google Patents

Description

  The present invention relates to a bending vibration piece including a pair of vibrating arms, a method for manufacturing the bending vibration piece, and a vibration device, an electronic apparatus, and a moving body including the bending vibration piece.

  Various types of flexural vibration pieces used as clock signal sources for computers, mobile phones, small information devices, and the like are known. Among them, the tuning fork-type bending vibration piece is characterized in that it is not easily affected by vibration leakage and is relatively easy to downsize because the form of the vibration part and the support part are different.

  However, due to the recent strong trend toward miniaturization, even the tuning fork-type bending vibration piece having the above-described characteristics cannot obtain desired characteristics unless measures are taken against vibration leakage. Among such actual situations, a tuning fork-type bending vibration piece suitable for downsizing and high performance is disclosed in Patent Document 1. The flexural vibration piece disclosed in Patent Document 1 is basically based on a configuration in which a support arm is provided between two vibration arms extending from one end of a base, and an electrode pad for connection is disposed on the support arm. It is a thing. By setting it as such a structure, the distance to the electrode pad used as a vibrating arm and a support part becomes long, and a vibration leak can be suppressed. In addition, the bending vibration piece disclosed in Patent Document 1 further describes that a vibration arm is formed with a groove extending over the entire width in the width direction to suppress the occurrence of vibration leakage.

  In a bending vibration piece having a configuration in which a support arm is provided between vibration arms, a connecting portion with a wafer-side support portion is provided on the distal end side of the support arm in the manufacturing process. In the manufacturing process of the bending vibration piece, the frequency characteristic in the wafer state is inspected before the bending vibration piece is separated. For this reason, by setting the connecting portion to the tip side of the support arm, the frequency characteristic inspection in the wafer state and the position of the support portion after being separated into pieces are approximated, resulting in a change in the support position. There is an advantage that a change in frequency characteristics is small.

  Further, by arranging the connecting portion at the tip of the support arm, the space occupied by one flexural vibration piece in the wafer is not wasted and the mass productivity is excellent.

JP 2011-15101 A

  However, in the bending vibration piece configured as disclosed in Patent Document 1, when the bending vibration piece is further downsized, the bending vibration frequency is maintained at a predetermined frequency (for example, 32.768 kHz). Therefore, it is necessary to increase the mass on the tip side of the vibrating arm. Such a problem can be solved by using a so-called hammer head type in which the width of the tip side of the vibrating arm is wide.

  However, when the form of the vibrating arm is a hammer head type, if the bending vibrating piece is to be realized in a desired size, it is secured between the hammer heads of the two vibrating arms, that is, on the tip side of the support arm. I have to make the space narrower than before. For this reason, if a connection portion with the wafer side support portion is provided on the distal end side of the support arm, it becomes difficult to give the connection portion sufficient strength to withstand an impact.

  Accordingly, the present invention provides a flexural vibration piece with good productivity, in which a support arm can be disposed between a pair of vibrating arms even when a connecting portion cannot be provided on the support arm. This is the first purpose. In addition, a second object of the present invention is to provide a method for manufacturing a bending vibration piece in which a connecting portion is provided at a base portion. Furthermore, a third object of the present invention is to provide a vibration device, an electronic apparatus, and a moving body using the bending vibration piece.

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.
A bending vibration piece according to an aspect of the present invention includes a base, a first vibrating arm and a second vibrating arm extending from one end of the base, and an extension of the vibrating arm from the one end of the base. A support arm that extends along a protruding direction and is disposed between the first vibrating arm and the second vibrating arm in a width direction orthogonal to the extending direction; and the one end of the base portion A plurality of protrusions provided on the other end opposite to the taper, and a tapered portion provided at a connection portion with the base of the vibrating arm, passing through the center of the width of the support arm The distance from the center line along the extending direction of the support arm to the end of the base in the width direction is L, and the center of the width of the tapered portion located on the support arm side from the center line the distance to the case of the X _1, wherein the plurality of protrusions, from the center line Wherein the distance along the width direction is provided on the other end of the region excluding the range less than large X _{1 +} 0.1 L from X ₁ -0.1L.
In the bending vibration piece according to another aspect of the present invention, the plurality of protrusions are symmetrically located with respect to a center line passing through the center of the width of the support arm and extending in the extending direction of the support arm. It is characterized by that.
In the bending vibration piece according to another aspect of the invention, the first vibrating arm includes a first arm portion extending from the base portion, and a side opposite to the base side of the first arm portion. A first widened portion having a width wider than the first arm portion, a second vibrating arm, a second arm portion extending from the base portion, and the second arm portion. A second widened portion provided at a distal end of the arm portion opposite to the base side and having a width larger than that of the second arm portion, and a distal end of the support arm opposite to the base side However, in the extending direction, the space between the first widened portion and the second widened portion is between the narrowest position and the base portion.
In the bending vibration piece according to another aspect of the invention, the other end of the base portion has a reduced width portion whose width gradually decreases in a direction opposite to the extending direction of the support arm. It is characterized by.
The manufacturing method of the bending vibration piece according to an embodiment of the present invention includes a base, first and second vibrating arms extending from one end of the base, and the vibrating arm from the one end of the base. A support arm that extends along the extending direction and is disposed between the first vibrating arm and the second vibrating arm in a width direction orthogonal to the extending direction; and A flexural vibration piece having a tapered portion provided at a connection portion with the base portion, a support portion disposed on the other end side of the base portion, and the other end side of the base portion, A plurality of connecting portions which are provided at positions symmetrical with respect to a center line passing through the center of the width and extending along the extending direction of the supporting arm, and connecting the base portion and the supporting portion; Including the step of preparing the provided structure and the step of cutting the connecting portion, The distance from the line to the end portion in the width direction of the base portion is L, from the center line, the distance to the center of the width of the tapered portion positioned on the supporting arm side when the X _1, said plurality connection of the the distance along the width direction from the center line is provided on the other end of the region excluding the range less than large X _{1 +} 0.1 L from X ₁ -0.1L It is characterized by.
According to another aspect of the present invention, there is provided a bending vibration piece manufacturing method in which the other end of the base portion of the bending vibration piece is contracted so that a width gradually decreases in a direction opposite to an extending direction of the support arm. A width portion is formed.
The manufacturing method of the bending vibration piece according to another embodiment of the present invention includes a step of adjusting a vibration frequency of the bending vibration piece after the step of preparing the structure and before the cutting step. It is characterized by including.
A vibrating device according to an aspect of the present invention includes the bending vibration piece.
An electronic apparatus according to an aspect of the present invention includes the bending vibration piece.
The mobile body which concerns on a certain form of this invention is provided with the said bending vibration piece.

  Application Example 1 A base, a first vibrating arm extending from one end of the base, a second vibrating arm aligned with the first vibrating arm in plan view, and the first vibration A flexural vibration piece having a support arm between the arm and the second vibrating arm and extending from the one end side of the base portion, wherein a plurality of protrusions are provided on the other end side of the base portion; Bending vibration piece characterized by

  According to the configuration as described above, even if the connecting portion cannot be provided on the support arm, the support arm is arranged between the pair of vibrating arms, and the bending with good productivity is achieved. A vibrating piece can be formed.

  [Application Example 2] The bending vibration piece according to Application Example 1, wherein the plurality of protrusions are located symmetrically with respect to a longitudinal center line of the support arm.

  According to such a configuration, in a state where the left and right vibrating arms are flexibly vibrating in a balanced manner with the support arm as the center, it is possible to suppress a change in moment due to the influence of the plurality of protrusions, and to prevent occurrence of vibration leakage. Can be reduced.

Application Example 3 A connecting portion with a base portion of the vibrating arm is provided with a taper portion, with a direction along a direction orthogonal to the extending direction of the first vibrating arm being a width direction, The plurality of projecting portions have a center in the width direction in the tapered portion located closer to the center line from the center line, where L is a distance from the center line of the support arm to the end in the width direction of the base portion. the distance to the case of the X _1, X ₁ - and characterized by providing in the region of the other end except for between away from largely from away to less than X ₁ + 0.1 L 0.1 L The bending vibration piece according to Application Example 1 or 2.

  According to such a configuration, it is possible to configure a flexural vibration piece in which the occurrence of vibration leakage is extremely increased even when the arrangement position of the protruding portion is in a line-symmetrical relationship with the support arm as a base point. Can be avoided.

Application Example 4 The first vibrating arm protrudes in the extending direction of the first arm from the first arm extending from the base, and from the tip of the first arm, and A first widened portion projecting along the direction of alignment with the second vibrating arm, the second vibrating arm extending from the base, and the second arm A second widened portion projecting in the extending direction of the second arm portion from the distal end of the arm portion and projecting along the direction in which the first vibrating arms are arranged, and the distal end of the support arm is It is the extending direction of the support arm, and is provided between the base portion and the base portion, the first widened portion and the second widened portion between the narrowest portion and the base portion. The bending vibration piece according to any one of Application Examples 1 to 3.
According to such a structure, it can contribute to size reduction of a vibration piece.

  Application Example 5 The other end of the base portion protrudes in a direction opposite to the extending direction of the support arm, and the length in the width direction gradually decreases toward the length in the protruding direction. The bending vibration piece according to any one of Application Examples 1 to 4, wherein the bending vibration piece has a reduced width portion.

  According to such a configuration, the vibration transmitted to the base due to the bending vibration of the vibrating arm is attenuated (relaxed / absorbed) by the reduced width portion, so that the vibration energy leaking from the support arm is reduced. Therefore, vibration leakage can be extremely reduced as compared with a bending vibration piece having a base portion without a reduced width portion as in this application example. In addition, the difference in vibration characteristics between the bending vibration piece in the wafer state and the bending vibration piece fixed to the package can be reduced.

  Application Example 6 A first vibrating arm extending from one end side of the base, a second vibrating arm aligned with the first vibrating arm in a plan view, and the first vibrating arm and the second A bending vibration piece having a support arm extending from the one end side of the base portion, a support portion disposed on the other end side of the base portion, and a direction in which the support arm extends. A structure preparation for preparing a structure including a connecting portion connecting the base portion and the support portion at a symmetrical position on the other end side of the base portion with a center line along the base line as a base point The manufacturing method of the bending vibration piece characterized by including the process and the process of cut | disconnecting the said connection part.

  According to such a method, even when the connecting portion cannot be provided on the support arm, the productivity of the flexural vibration piece can be improved with the configuration in which the support arm is disposed between the pair of vibrating arms. Can be maintained.

Application Example 7 In the structure preparation step, a connecting portion of the vibrating arm with the base portion includes a taper portion, and the pair of connecting portions has an end in the width direction of the base portion with the center line as a base point. the distance to the part is L, the distance from the center line to the center of the tapered portion positioned on the center line closer to the case of the X _1, X ₁ - X ₁ from significantly away from the 0.1 L + The method of manufacturing a flexural vibration piece according to Application Example 6, which is a step of preparing a structure at a position excluding a space apart to less than 0.1 L.

  According to such a method, even if the arrangement position of the projecting portion (connecting portion) is in a line-symmetrical relationship with the support arm as the base point, the bending vibration piece in which the occurrence of vibration leakage is extremely increased Can be avoided.

  Application Example 8 In the structure preparation step, the other end of the base portion protrudes in a direction opposite to the extending direction of the support arm, and the first vibration is directed toward the protruding direction. The application example 6 or 7 is a step of preparing a structure including a reduced width portion in which a width along an arrangement direction of the arm and the second vibrating arm is gradually reduced. Manufacturing method of bending vibration piece.

  According to such a method, the vibration transmitted to the base due to the bending vibration of the vibrating arm is attenuated (relaxed / absorbed) by the reduced width portion. As compared with a bending vibration piece that is not provided, it is possible to manufacture a bending vibration piece in which the vibration of the base is suppressed to be small. Therefore, vibration leakage can be extremely reduced as compared with a bending vibration piece having a base portion without a reduced width portion as in this application example.

  Application Example 9 Any of Application Examples 6 to 8 including a step of adjusting a vibration frequency of the bending vibration piece after the structure preparation step and before the cutting step. A method of manufacturing a bending vibration piece as described in one example.

  According to such a method, since the vibration frequency difference of the bending vibration piece between the cutting process and the subsequent state in the state of the structure is small, the vibration frequency can be efficiently reduced even in the structure having no connection portion on the support arm. Adjustments can be made.

[Application Example 10] A vibration device comprising the bending vibration piece according to any one of Application Examples 1 to 5.
According to the above configuration, a vibration device having excellent oscillation characteristics is provided by the flexural vibration piece having reduced vibration leakage and reduced Q value reduction and excellent vibration characteristics.

Application Example 11 An electronic apparatus comprising the flexural vibration piece according to any one of Application Examples 1 to 5.
According to the above configuration, since the bending vibration piece that reduces vibration leakage and reduces the decrease in the Q value is used, an electronic device that can stably exhibit desired performance is provided.

Application Example 12 A moving body comprising the flexural vibration piece according to any one of Application Examples 1 to 5.
According to the said structure, according to the said structure, since the bending vibration piece which reduced the leak of vibration and reduced the Q value was used, the mobile body which can exhibit desired performance stably is provided.

It is a top view of the bending vibration piece of this invention. It is the elements on larger scale of the bending vibration piece of this invention. It is a top view of the bending vibration piece of a modification. It is a figure for demonstrating the manufacturing method of the bending vibration piece of this invention. It is a graph which shows the relationship between the vibration leak index | exponent of the bending vibration piece of this invention, and the formation location of the connection trace of a base other end.

  Embodiments of a flexural vibration piece (also referred to as a vibration piece), a vibration device, an electronic device, and a moving body of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a plan view of a flexural vibration piece of the present invention. FIG. 2 is a partially enlarged view of the flexural vibration piece of the present invention. As shown in FIG. 1, the flexural vibration piece 10 of the present invention includes a base portion 20, a pair of vibrating arms 30 extending from one end 22 of the base portion 20, and a pair of vibrating arms 30. A support arm 40 extending from one end 22 of the base 20 along the extending direction is provided.
The base 20 shown in FIG. 1 has a side surface on the back side with respect to one end 22 as the other end 24, and the other end 24 side has a connecting mark 50 (50a, 50b) that is a protruding portion. Yes. The other end 24 extends in a direction perpendicular to the direction in which the vibrating arm 30 extends. In the case of this embodiment, the one end 22 is, for example, a linear region existing between the vibrating arm 30 and the support arm 40 and is formed so that the one end 22 and the other end 24 are parallel to each other. . Such a base 20 has the same length in the direction parallel to the extending direction of the vibrating arm 30 and the support arm 40 in the entire region of the one end 22 and the other end 24.

  The pair of two resonating arms 30 each have a base end where the arm portion 32 extends in parallel from the base end toward the tip and is connected to one end 22 of the base 20. Groove portions 34 having, for example, a substantially rectangular shape in plan view are formed on the front and back main surfaces of the vibrating arm 30 as grooves extending in the longitudinal direction.

  The vibrating arm 30 is formed with a hammer head portion 36 as a weight portion at the tip of the arm portion 32 as a widened portion having a width larger than the width along the direction orthogonal to the extending direction of the vibrating arm 30 in plan view. Yes. The hammer head portion 36 has a width wider than the width of the arm portion 32 and is formed in a substantially rectangular shape in plan view, but is not limited to this shape, and faces the tip of the hammer head portion 36. The width may be gradually or stepwise widened. The vibrating arm 30 having the hammer head portion 36 vibrates more than the conventional type even if the length extending from the base portion 20 is shorter than the conventional type for the purpose of downsizing the vibrating piece. By setting the mass on the distal end side of the arm 30 to be large, it is possible to suppress bending vibration at a higher frequency than necessary. For example, it is possible to maintain the same vibration regardless of the length of the vibrating arm 30. That is, if the hammer head portion 36 is provided on the vibration arm 30, the number of times the vibration arm 30 bends and deforms per unit time is adjusted by changing the mass of the hammer head portion 36, and a desired bending vibration frequency can be easily obtained. be able to. In addition, in the length of the proximal half of the vibrating arm 30 that is flexibly vibrated, the width of the vibrating arm 30 is predominantly the effect of rigidity against bending deformation, whereas the length of the half of the distal end side of the vibrating arm 30 is large. In this case, since the mass load effect predominates in the width of the vibrating arm 30, the hammer head portion 36 is formed in the region on the tip half side of the vibrating arm 30. It is desirable to include a highly effective tip region. Further, the length of the hammer head portion 36 formed at the tip of the vibrating arm 30 with respect to the entire length of the vibrating arm 30 is set to 30% to 50%. Further, the width of the arm portion 32 is increased so as to compensate for the decrease in the bending vibration frequency due to the hammer head. As a result, the thermoelastic loss is reduced and the Q value is remarkably increased. Further, the length of the hammer head portion 36 is 1.2% or more and smaller than 30%, so that the excitation formed on the arm portion 32 is increased. Since the area of the electrode (described later) can be increased, the CI value is drastically reduced.

  Exciting electrodes (not shown) are formed on the surfaces of the arm portion 32 and the groove portion 34, and the vibrating arm 30 is formed at a predetermined frequency by applying a predetermined driving voltage to the excitation electrode via an electrode pad 44 described later. It bends and vibrates in directions toward or away from each other.

  The support arm 40 is between the pair of vibrating arms 30, and an arm portion 42 extends from the base portion 20 at one end 22 along the extending direction of the vibrating arm 30. The length of the support arm 40 in the extending direction is shorter than the length of the vibrating arm 30 in the extending direction, and the distal end of the support arm 40 is disposed closer to the base 20 than the connection portion between the arm portion 32 and the hammer head portion 36. It is set to be. That is, it is desirable that the support arm 40 does not exist between the two hammer head portions 36, but it is sufficient that the support arm 40 does not reach the narrowest portion between the two hammer head portions 36. When the support arm 40 exists between the hammer head portions 36, the width between the hammer head portions 36 is the sum of the width of the support arm 40 and twice the amount of movement of the hammer head portion 36 due to the bending of the vibrating arm 30. A distance of at least is required. On the other hand, by keeping the length of the support arm 40 within the range of the arm portion 32, the width between the hammer head portions 36 is twice the distance of the movement amount of the hammer head portion 36 due to the bending of the vibrating arm 30. If there is at least, it will be sufficient, and it can contribute to size reduction of the bending vibration piece 10. A pair of electrode pads 44 is formed on the bottom surface of the support arm 40 (the broken line in FIG. 1 indicates the bottom surface side). The bending vibration piece 10 can be adhered to a mounting surface such as a package using a conductive adhesive, and the pair of vibration arms 30 can be fixedly supported by the central support arm 40. In addition, the minimum distance between the support arm 40 and the vibrating arm 30 is preferably longer than the minimum distance between the electrode pad 44 and the hammer head portion 36. By doing so, even if the conductive adhesive formed on the electrode pad 44 is formed larger, the possibility of adhering to the vibrating arm 30 is lower than that of the hammer head portion 36, that is, the loss is larger than that of quartz. Since the possibility that the conductive adhesive adheres to the bending deformation portion of the vibrating arm 30 having a great influence on the vibration characteristics is reduced, no fatal characteristic deterioration is caused.

  The connecting positions of the vibrating arm 30 and the supporting arm 40 and the one end 22 of the base 20 are respectively reduced in plan view, and the width of the vibrating arm 30 and the width of the supporting arm 40 decrease from the boundary with the base 20 toward the extending direction. Tapered portions 38 and 46 are formed. The arm portion 32 of the vibrating arm 30 and the arm portion 42 of the support arm 40 extend in a substantially straight line so as to be parallel to each other from the proximal end to the distal end. A region where the width of the support portion 40 is narrow may be provided. By doing this, the vibration frequency of the mode in which the two vibrating arms 30 both bend and vibrate in the same direction (hereinafter referred to as the in-phase mode) is changed to the mode in which the two vibrating arms 30 repeat alternately approaching and separating from each other (hereinafter referred to as the following mode). Main mode) can be separated from the vibration frequency, and the coupling strength between the in-phase mode and the main mode can be reduced, thereby preventing the main mode vibration leakage from increasing. In particular, when the vibration frequency of the common mode is f1 and the vibration frequency of the main mode is f0, | f1-f0 | / f0 ≧ 10%, more preferably | f1-f0 | / f0 ≧ 20%, The coupling between the two can be greatly suppressed. The arm portion 32 of the vibrating arm 30 and the arm portion 42 of the support arm 40 are not bent at a right angle or an acute angle from the distal end to the proximal end at the connection position with the one end 22 of the base portion 20, but the width thereof. Rounded taper portions 38 and 46 may be provided so that the diameter gradually increases. The tapered portions 38 and 46 are formed between both side surfaces of the vibrating arm 30 and the support arm 40 and one end 22 of the base portion 20. By providing the tapered portions 38 and 46, it is possible to avoid the concentration of strain when bending vibration occurs, that is, avoid the concentration of temperature change (temperature rise or temperature drop) accompanying the occurrence of strain, and flow of heat. Therefore, the increase in thermoelastic loss can be suppressed, the strength of the connection position can be increased, and the impact resistance can be improved. Note that the width of the vibrating arm 30 of the present embodiment is a region including the width of the arm portion 32 of the vibrating arm 30 and the width of the tapered portions 38 formed on both side surfaces of the arm portion 32. In addition, the width of the support arm 40 in the present embodiment is a region including the width of the arm portion 42 of the support arm 40 and the width of the tapered portions 46 formed on both side surfaces of the arm portion 42.

  The other end 24 of the base portion 20 is formed with a plurality of connection marks protruding in the direction opposite to the extending direction of the vibrating arm 30 and the support arm 40 (two in this embodiment). The connection marks 50 a and 50 b of the present embodiment are formed on the other end 24 of the base 20 at positions that are line-symmetric with respect to the support arm 40. Here, the connection marks 50a and 50b are remnants when the bending vibration piece 10 is cut out from a connection portion in a wafer or the like in the manufacturing process of the bending vibration piece 10.

  Although the lengths of the connection marks 50a and 50b may change variously, as an example, the protruding length from the other end 24 of the base portion 20 is about 30 μm. The longer the length of the connecting portion, the worse the plate-cutting property of the bending vibration piece 10 (the number of bending vibration pieces 10 obtained from one wafer decreases), and the vibration frequency depends on the length of the connecting portion. When the vibration frequency coincides with the vibration frequency of the pair of vibration arms 30, the modes at both vibration frequencies are combined, so the length of the connecting portion is made as short as possible. The widths of the connection marks 50 a and 50 b are set smaller than the widths of the vibrating arm 30 and the support arm 40. Further, as a method of cutting the bending vibration piece 10 from a wafer or the like, when the bending vibration piece 10 is broken by applying force to the bending vibration piece 10 from the upper side to the lower side in FIG. Provide a part where stress is intentionally concentrated by forming a non-penetrating groove partly or entirely to reduce the thickness of the connecting part, or partially reducing the width of the connecting part. If it cut | disconnects in this, the length of the connection mark 50 can be stabilized. In particular, as in the case of forming a groove, a structure in which the thickness along the direction in which the force is applied is partially reduced is easy to cut.

2, the length from the center line in the extending direction of the support arm 40 to the end of the base 20 is L. X is the length from the center line of the support arm 40 to the location where the connection marks 50a, 50b are formed at the ends of the base 20 (the center line in the protruding direction of the connection marks 50a, 50b), and the center of the tapered portion from the center of the support arm Is defined as X ₁ .

  FIG. 3 is a plan view of a bending vibration piece according to a modification. As shown in the figure, the bending vibration piece 10A of the modification is different from the bending vibration piece 10 shown in FIG. Other configurations are the same as those of the bending vibration piece 10 shown in FIGS. 1 and 2, and the same reference numerals are given and detailed description thereof is omitted. In the bending vibration piece 10A of the modified example, the other end 24A of the base portion 20A protrudes in the direction opposite to the extending direction of the support arm 40, and the length in the direction in which the vibrating arms 30 are arranged gradually decreases in the protruding direction. Has a reduced width portion. According to the bending vibration piece 10A of the modified example having such a configuration, the vibration in the base 20A caused by the bending vibration of the vibrating arm 30 is canceled (relaxed / absorbed) by the reduced width portion, and thus connected to the base 20A. The vibration of the support arm 40 is reduced. Accordingly, vibration leakage can be suppressed when the fixing portion to be mounted on the package is provided on the support arm 40 as compared with the bending vibration piece 10 having the base portion 20 having no reduced width portion.

  In addition, the bending vibration pieces 10 and 10A of the present embodiment are made of a known photo-etching technique using a piezoelectric material such as quartz, lithium tantalate, lithium niobate, lithium tetraboat, potassium niobate, potassium phosphate, or langasite. And can be formed into a desired outer shape. As an example, in the case of forming with a crystal having an X axis (electrical axis), a Y axis (mechanical axis), and a Z axis (optical axis) as crystal axes, 0 ° or more and 15 ° or less with respect to the Y axis centering on the X axis If the coordinate axis forming the angle is the Y ′ axis, the direction perpendicular to the Y ′ axis and the X axis is generally oriented in the thickness direction, and the Y ′ axis direction is oriented in the longitudinal direction of the vibrating arm (hereinafter referred to as this). Called a crystal Z plate).

  The bending vibration pieces 10 and 10A having such a configuration are manufactured by the following process when using quartz as an example. The bending vibration pieces 10 and 10A are manufactured on the basis of a wafer-like base material having a flat plate shape by polishing the surface of a quartz crystal Z plate. A protective film in which a Cr film or a Ni film is formed on the surface of the quartz wafer 60 and further an Au film is laminated on the surface is formed by vapor deposition or sputtering. Then, after applying a resist film on the surface of the protective film, the resist film is patterned by photolithography into a shape slightly wider than the outer shape of the bending vibration pieces 10 and 10A. Next, the protective film is etched away using the patterned resist film as a mask. After the resist film is peeled off, the resist film is applied again, and the outer shape and the groove shape constituting the support portion 62 and the bending vibration pieces 10 and 10A connected by the plurality of connecting portions 51 are patterned. In this state, the exposed portion of the quartz wafer 60 is etched with hydrofluoric acid to form the outer shapes of the bending vibration pieces 10 and 10A, the connecting portion 51, and the support portion 62 (see FIG. 4). Here, the connecting portion 51 is provided between the other end 24 of the base portion 20 and the support portion 62.

  Next, the protective film formed in the groove 34 is etched. The crystal surface thus etched and exposed corresponds to the planar shape of the groove 34 formed in the vibrating arm 30. Then, the exposed portion of the quartz wafer 60 is half-etched with hydrofluoric acid for a predetermined time to form a groove 34 in the vibrating arm 30. After the etching of the groove 34, the resist film and the protective film are peeled off.

  The electrode is formed as follows. A Cr film or Ni film is formed on the entire surface of the quartz wafer 60, an electrode film having an Au film disposed thereon is formed, and a resist film corresponding to the pattern of the excitation electrode is formed on the electrode film. Then, the excitation film is formed by etching the electrode film. After etching the electrode, the resist film is peeled off.

  Next, a weight is attached to the tip of the vibrating arm 30. In this method, a metal film such as Au is formed as a weight adjusting film for frequency adjustment on a part or the entire surface of the hammer head portion 36 by vapor deposition or sputtering.

In the rough adjustment of the frequency, a part of the weighting film is irradiated with a laser beam or the like to partially evaporate, and the mass of the hammer head portion 36 is adjusted. Thereby, the bending vibration frequency of the plurality of bending vibration pieces 10 formed on the quartz wafer 60 can be roughly adjusted so as to approach a desired frequency (for example, 32.768 kHz).
Finally, the bending vibration pieces 10 and 10A are separated. That is, the connection part 51 which connects the support part 62 and the bending vibration pieces 10 and 10A in the crystal wafer 60 is cut, and the bending vibration pieces 10 and 10A arranged in parallel are divided into individual pieces. Due to this separation, connection marks 50a and 50b are formed at the other ends of the base portions 20 and 20A.

  FIG. 5 is a graph showing the relationship between the vibration leakage index of the flexural vibration piece of the present invention and the location where the connection mark is formed at the other end of the base. Here, as an example, the shape of the bending vibration piece 10 used for the calculation is 860 μm in total length, 248 μm in length L from the center line in the extending direction of the support arm 40 to the end of the base 20, and the center of the support arm 40. The length from the line to the side of the support arm 40 is 50 μm, and the length from the center line of the support arm 40 to the side of the vibrating arm 30 on the support arm 40 side (the side on the inside of the vibrating piece) is 155 μm. The length from the center line of the arm 40 to the side of the vibrating arm 30 on the end side of the base 20 (side of the outside of the vibrating arm 30) is 207 μm, and the connection mark 50a at the other end of the base 20 from the center line of the support arm 40 , 50b to the formation location (the center line in the protruding direction of the connecting marks 50a, 50b) is X, the connecting marks 50a, 50b are square in plan view, the length in the protruding direction is 30 μm, and the groove 34 The depth is 45 μm, the width of the hammer head part 36 is 198 μm, The length of the summer head portion 36 is 237 μm, and the flexural vibration frequency is in the vicinity of 32.768 kHz. The vibration leakage was calculated as follows assuming that the bending vibration piece 10 was mounted on a ceramic package with the silicon conductive adhesive having a thickness of 20 μm mounted on the package.

The elastic energy resulting from the bending vibration of the bending vibration piece 10 reaches the conductive adhesive via the support arm 40 and is virtually provided on the back surface of the conductive adhesive (the side opposite to the bending vibration piece 10). The calculation is made on the condition that the bending vibration piece 10 is not returned while being transmitted to the semi-infinite medium having the material constant of the package.
Since this energy transmitted to the semi-infinite medium does not contribute to bending vibration again in the bending vibration piece 10, it becomes a loss due to vibration leakage. The Q value considering only the loss due to the vibration leakage is defined as QLeak (when the vibration leakage increases, QLeak decreases). Further, as can be easily imagined from the mechanism described later, the present invention does not depend on the absolute value of the dimensions, the bending vibration frequency, or the material described above.

  The vertical axis of the graph is the vibration leakage index (Q0 / QLeak). Here, Q0 is a Q value considering only vibration leakage when the other end 24 of the base 20 does not have the connection marks 50a and 50b, and QLeak is two connection marks 50a and 50b at the other end 24 of the base 20. The Q value considering only the vibration leakage when formed is shown. The horizontal axis of the graph is the location (X / L) where the connection marks 50a and 50b are formed at the other end 24 of the base 20, and when X / L = 0, the center line of the support arm 40 and the center of the connection marks 50a and 50b are located. When X / L = 1, the end of the base 20 and the center of the connection marks 50a and 50b overlap. The ◆ plot is a graph showing an example of a vibrating piece in which the one end 22 and the other end 24 of the base 20 are formed in parallel with the base body interposed therebetween, like the flexural vibrating piece 10 shown in FIG. is there. Also, the ▪ plot is a graph showing an example of a vibrating piece in which the shape of the other end 24A of the base portion 20A is formed with a reduced width portion, like the bending vibrating piece 10A shown in FIG. In the bending vibration piece 10 and the bending vibration piece 10A, since the suppression of vibration leakage by the reduced width portion is very large, when the display scale is the same, vibration due to the difference in the formation positions of the connection marks 50a and 50b. Changes in leak index become difficult to read. For this reason, in FIG. 5, the scale of the bending vibration piece 10 is shown on the left vertical axis in the drawing, and the scale of the bending vibration piece 10A is shown on the right side of the drawing.

In FIG. 5, when the vibration leakage index is smaller than 1.0, the vibration leakage is smaller than that of the bending vibration piece having no connection trace at the other end of the base. In the case of the bending vibration piece 10 shown in FIG. 1, the vibration leakage index greatly exceeds 1.0 when the connection marks 50 a and 50 b exist in the range of 0.46 <X / L <0.66. When this range is expressed as a percentage, 46% <X / L <66%. This range is generally the region at the other end of the base corresponding to the tapered portion forming position formed on the support arm side of the vibrating arm formed at one end of the base. More specifically shown, it supports the distance from the center of the arm to the center of the tapered portion in the case of the X _1, support the center position of the arm 40 from the center of the base supporting arm 40 X ₁ - 0.1 L It is a region indicated by a distance that is larger and smaller than X ₁ + 0.1L.

  The vibrating arm 30 is configured to bend and vibrate in a direction in which the vibrating arms 30 approach or separate from each other at a predetermined frequency by applying a predetermined driving voltage to the excitation electrode. When the pair of vibrating arms 30 is bent and deformed in opposite phases, the support arm 40 is fixed to the package via the electrode pad 44 and the conductive adhesive, so that the base portion 20 is bent and deformed in the extending direction of the vibrating arms 30. In particular, the portion of the base 20 located between the base end of the support arm 40 and the base end of the vibrating arm 30 and the base 20 located in the direction opposite to the direction in which the vibrating arm 30 extends are connected thereto. This part will be bent greatly. In the bending vibration piece 10 that supports the support arm 40 between them, the bending deformation of the compressive or tensile stress is repeatedly generated between one end and the other end of the base 20 due to the bending operation of the vibrating arm 30. Yes. For this reason, when a weight such as a connection trace is formed at the other end of the base portion 20, the moment is changed by the connection trace in a state where the left and right vibrating arms 30 are flexibly oscillating with the support arm 40 at the center. It becomes a balance and vibration leakage is likely to occur. When the connection marks 50a and 50b exist in the range of 46% <X / L <66%, it can be said that such an effect is remarkably exhibited.

On the other hand, even when the connection marks 50a and 50b are disposed at the other end of the base portion 20, the pair of vibrating arms 30 are arranged symmetrically with respect to the center of the support arm 40 in a state where the pair of vibrating arms 30 is flexibly vibrating in a balanced manner. When the change in the moment is suppressed by the plurality of connection marks 50a and 50b, the occurrence of vibration leakage can be reduced. That, coupled marks 50a, 50b and _{46% <X / L <66} % - so that (X 1 0.1 L greater than _X 1 + 0.1 L smaller range) than the range of the other end of the base portion 20 This is the case.

On the other hand, in the case of the bending vibration piece 10A shown in FIG. 3, it can be read from FIG. 5 that the vibration leakage index is small in the entire region regardless of the place where the connection marks 50a and 50b are arranged. . Note that Q0 in the graph is also the same value as Q0 in the bending vibration piece used when the vibration leakage index of the bending vibration piece 10 is shown.
As described above, even in the bending vibration piece 10A in which the other end of the base portion 20A is provided with a slope that forms a mountain shape from the end portion toward the center, vibration leakage is likely to occur depending on the arrangement position of the connection marks 50a and 50b. There is a change. Specifically, similar to the bending vibration piece 10, the vibration leakage index greatly increases in the range of 46% <X / L <66% in percentage display. Therefore, even in the bending vibration piece 10A, connecting traces 50a, 50b, at the other end of the base portion 20A, 46% <X / L <66% of the range _(X 1 - from greater away from 0.1L X ₁ + is preferably arranged in a range excluding a range up to less than 0.1 L).

  The present invention is not limited to the above embodiments, and can be implemented with various modifications or changes within the technical scope thereof. For example, the pair of two vibrating arms can be applied even when the arm portion is extended substantially linearly from the proximal end to the distal end without forming the hammer head portion at the distal end.

  Further, the flexural vibration piece of the present invention can be mounted on packages having various structures, and can be applied to various vibration devices other than vibrators such as an oscillator combined with a circuit element having an oscillation circuit.

  Further, the flexural vibration piece 10 or 10A of the present invention is combined with a circuit element having an oscillation circuit, thereby enabling a digital mobile phone, a personal computer (mobile personal computer), an electronic watch, a video recorder, a video camera, a television, a digital still. Cameras, inkjet discharge devices (for example, inkjet printers), laptop personal computers, car navigation devices, pagers, electronic notebooks (including those with communication functions), electronic dictionaries, calculators, electronic game devices, word processors, workstations, videophones , Crime prevention TV monitor, electronic binoculars, POS terminal, medical equipment (for example, electronic thermometer, blood pressure monitor, blood glucose meter, electrocardiogram measuring device, ultrasonic diagnostic device, electronic endoscope), fish detector, various measuring devices, instruments ( In example, vehicle, aircraft, gauges of a ship), can be used widely as an electronic device such as a flight simulator.

  Moreover, the bending vibration pieces 10 and 10A of the present invention are mounted on an automobile. Bending vibration pieces 10, 10A are keyless entry, immobilizer, car navigation system, car air conditioner, anti-lock brake system (ABS), airbag, tire pressure monitoring system (TPMS: Tire Pressure Monitoring System), engine control, The present invention can be widely applied to electronic control units (ECUs) such as battery monitors and body posture control systems for hybrid vehicles and electric vehicles.

10, 10A ......... Bending vibration piece, 20, 20A ......... Base, 22, 22A ......... One end, 24, 24A ......... Other end, 30 ......... Vibrating arm, 32 ......... Arms, 34 ......... groove, 36 ......... hammer head, 40 ......... support arm, 42 ......... arm, 44 ......... electrode pad, 50a, 50b ......... connection mark, 51 ......... connection, 60... Crystal wafer, 62.

Claims (10)

The base,
A first vibrating arm and a second vibrating arm extending from one end side of the base;
It extends along the extending direction of the vibrating arm from the one end side of the base, and is arranged between the first vibrating arm and the second vibrating arm in the width direction orthogonal to the extending direction. The supporting arm being
A plurality of protrusions provided on the other end opposite to the one end of the base;
A tapered portion provided at a connection portion with the base portion of the vibrating arm;
With
The distance from the center line passing through the center of the width of the support arm along the extending direction of the support arm to the end of the base in the width direction is L,
From the centerline, the distance to the center of the width of the tapered portion positioned on the supporting arm side when the X _1,
Wherein the plurality of protrusions provided on the other end side of a region in which the distance along the width direction except for the smaller range than larger X _{1 +} 0.1 L from X ₁ -0.1L from the center line bending vibration piece, characterized in that there.   2. The bending according to claim 1, wherein the plurality of projecting portions are in symmetrical positions with a center line passing through the center of the width of the support arm and extending in the extending direction of the support arm as a base point. Vibrating piece. The first vibrating arm is provided at a first arm portion extending from the base portion and a tip of the first arm portion on a side opposite to the base portion side, and more than the first arm portion. A first widened portion having a large width;
The second vibrating arm is provided at a second arm portion extending from the base portion and a tip of the second arm portion on the side opposite to the base portion side, and more than the second arm portion. A second widened portion having a large width,
The tip of the support arm on the side opposite to the base side is between the base and the position where the distance between the first widened portion and the second widened portion is narrowest in the extending direction. The bending vibration piece according to claim 1 , wherein the bending vibration piece is provided. The said other end of the said base part has the reduced width part which a width | variety reduces gradually toward the direction opposite to the extension direction of the said support arm, The any one of Claim 1 thru | or 3 characterized by the above-mentioned. The bending vibration piece according to 1. Base, the first vibrating arm and the second vibrating arm extending from one end of the base portion, and extends from the one end side of the front SL base along the extending direction of the vibrating arm, leaving the extension A support arm disposed between the first vibrating arm and the second vibrating arm in a width direction perpendicular to the direction, and a tapered portion provided at a connection portion between the vibrating arm and the base. A bending vibration piece provided; a support portion disposed on the other end side of the base portion; and the other end side of the base portion, passing through the center of the width of the support arm in the extending direction of the support arm. Providing a structure including a plurality of connecting portions that are provided at symmetrical positions with respect to a center line that is along, and that connect the base portion and the support portion; and
Cutting the connecting portion, and
The distance from the center line to the end of the base in the width direction is L,
From the centerline, the distance to the center of the width of the tapered portion positioned on the supporting arm side when the X _1,
Wherein the plurality of connecting portions, provided on the other end side of a region in which the distance along the width direction except for the smaller range than larger X _{1 +} 0.1 L from X ₁ -0.1L from the center line A method of manufacturing a flexural vibration piece, comprising: Wherein the other end of the base portion of the bending vibration piece, according to claim 5, characterized in that reduced width portion whose width toward the opposite direction is gradually reduced is formed with the extending direction of the support arm Manufacturing method of bending vibration piece. The bending according to claim 5 or 6, further comprising a step of adjusting a vibration frequency of the bending vibration piece after the step of preparing the structure and before the step of cutting. A method for manufacturing the resonator element. Vibrating device characterized in that it comprises a bending vibration piece according to any one of claims 1 to 4. An electronic apparatus comprising: a bending vibration piece according to any one of claims 1 to 4. Mobile, characterized in that it comprises a bending vibration piece according to any one of claims 1 to 4.

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