JP6652372B2 - A tuning fork crystal element and a crystal device on which the tuning fork crystal element is mounted. - Google Patents

Description

  The present invention relates to a tuning-fork type crystal element used for, for example, an electronic device and a crystal device on which the tuning-fork type crystal element is mounted.

  The tuning-fork type crystal element includes a crystal base and two flat-plate-shaped crystal vibrating portions extending in the same direction from the side surfaces of the crystal base. Further, the crystal device generates a specific frequency by causing a bending vibration by utilizing a piezoelectric effect of a tuning fork type crystal element. There has been proposed a crystal device including a tuning fork-type crystal element mounted on an electrode pad provided on a substrate via a conductive adhesive (for example, see Patent Document 1 below).

JP 2008-301297 A

  In the above-mentioned conventional tuning fork-type crystal element, downsizing of the tuning-fork-type crystal element is required with downsizing of the crystal device. Due to the downsizing of the tuning fork element, the distance between the crystal vibrating part of the tuning fork type crystal element and the part held by the conductive adhesive is shortened, the vibration of the crystal vibrating part is hindered, and the electrical characteristics deteriorate. There is a risk of doing this.

  The present invention has been made in view of the above problems, and has as its object to provide a tuning-fork type crystal element that can improve electrical characteristics.

A tuning fork-type crystal element according to one aspect of the present invention is a crystal base having a substantially rectangular shape, a crystal vibrating portion provided to extend from a side surface of the crystal base, and a position facing the side surface of the crystal base. A substantially rectangular crystal holding portion provided to extend from the side surface, one crystal supporting portion provided to extend in the same direction as the crystal vibrating portion from the side surface of the crystal holding portion, and a crystal vibrating portion. A pair of first grooves provided on the upper surface and the lower surface of the crystal holding portion from one side constituting the side surface at a position opposed to the side surface on which the portion is formed, and the upper surface, the lower surface, and the side surface of the crystal vibrating portion an excitation electrode provided on the quartz base from vibrating portion, provided toward the crystal holding unit and lens support portion, and the excitation electrode and electrically connected to the extraction electrode includes a first groove portion, quartz When the holding part is viewed in plan, The length of the first groove the crystal toward the vibrating portion direction is characterized in that is provided to be shorter than the length in the direction toward the vibrating portion of the first groove of the other.

A tuning fork-type crystal element according to one aspect of the present invention includes a substantially rectangular crystal base, a crystal vibrating portion provided to extend from a side surface of the crystal base, and a side surface at a position facing the side surface of the crystal base portion. A substantially rectangular crystal holding portion provided so as to extend further, one crystal supporting portion provided to extend from the side surface of the crystal holding portion in the same direction as the crystal vibrating portion, and a crystal vibrating portion A pair of first grooves provided on the upper surface and the lower surface of the crystal holding portion from one side constituting the side surface at a position opposed to the side surface where the crystal is formed, and the upper surface, the lower surface and the side surface of the crystal vibrating portion an excitation electrode provided, quartz base from vibrating portion, provided toward the crystal holding unit and lens support portion, and the excitation electrode and electrically connected to the extraction electrode includes a first groove portion, the crystal holding When the part is viewed in plan, The length in the direction toward the vibrating portion one groove is provided to be shorter than the length in the direction toward the vibrating portion of the first groove of the other. In such a tuning fork type crystal element, when the first groove portion is provided in the crystal holding portion in a plan view, the vibration is blocked by the first groove portion. The state of vibration can be rapidly attenuated, and vibration leakage from the crystal vibrating portion to the crystal holding portion can be reduced, and vibration inhibition from the contact portion to the crystal vibrating portion can be reduced. Therefore, the tuning fork type crystal element can improve the electrical characteristics.

It is an appearance perspective view showing the tuning fork type crystal element concerning a first embodiment. FIG. 3A is a plan view illustrating an upper surface side of a tuning fork crystal element included in the crystal device according to the first embodiment, and FIG. 3B is a plan view illustrating a lower surface side of the tuning fork crystal element included in the crystal device according to the first embodiment. FIG. FIG. 3A is a plan view showing an upper surface side of a tuning fork type crystal element constituting the crystal device according to the first embodiment connected to a connecting portion, and FIG. 3B is a tuning fork constituting the crystal device according to the first embodiment. It is a top view which shows the lower surface side in the state in which the type | mold crystal element was connected to the connection part. (A) It is a top view which shows the upper surface side of the tuning fork type crystal element which comprises the crystal device which concerns on the 1st modification of 1st Embodiment, (b) The crystal device which concerns on 1st modification of 1st Embodiment It is a bottom view showing the lower surface side of the tuning fork type crystal element which comprises. (A) It is a top view which shows the upper surface side of the tuning fork type crystal element which comprises the crystal device which concerns on the 2nd modification of 1st Embodiment, (b) It shows the crystal device which concerns on 2nd modification of 1st Embodiment. It is a bottom view showing the lower surface side of the tuning fork type crystal element which comprises. It is an exploded perspective view showing a crystal device concerning a second embodiment. It is a top view showing the state where the lid of the crystal device concerning a second embodiment was removed. (A) It is the top view which looked at the package which comprises the crystal device concerning 2nd embodiment from the upper surface, and (b) It is the top view which looked at the board | substrate of the package which comprises the crystal device which concerns on 2nd embodiment from the upper surface. is there. It is a bottom view showing the undersurface side of the package which constitutes the crystal device concerning a second embodiment. It is a top view showing the state where the lid of the crystal device concerning the first modification of a second embodiment was removed. FIG. 7A is a plan view of a package forming a crystal device according to a first modification of the second embodiment as viewed from above, and FIG. 7B is a package forming a crystal device according to a first modification of the second embodiment. FIG. 4 is a plan view of the substrate of FIG. (A) It is the top view which looked at the package which comprises the crystal device concerning the 2nd modification of 2nd Embodiment from the upper surface, (b) The package which comprises the crystal device concerning the 2nd modification of 2nd embodiment. FIG. 4 is a plan view of the substrate of FIG.

(First embodiment)
The tuning-fork type crystal element 120 according to the first embodiment includes a crystal base 121, a crystal holding part 122, a crystal vibrating part 123, and a crystal supporting part 124, as shown in FIGS. On the surface of the tuning-fork type crystal element 120, there are formed excitation electrodes 125a, 125b, 126a and 126b, extraction electrodes 127a and 127b, metal films 128a and 128b for frequency adjustment, and first grooves D1a and D1b. .

  The crystal base 121 is used to support a crystal vibrating part 123 and a crystal holding part 122 described later. The crystal base 121 has a rectangular coordinate system in which the electric axis is the X axis, the mechanical axis is the Y axis, and the optical axis is the Z axis. Is a substantially rectangular flat plate in a plan view in which the direction of the Z ′ axis rotated in the direction becomes the thickness direction.

  The crystal holding unit 122 is for holding and fixing the tuning fork type crystal element 120 on the package 110 together with a crystal support unit 124 described later. The crystal holding portion 122 is provided on a surface of the crystal base portion 121 facing the side surface on which the crystal vibrating portion 123 is formed. The crystal holding portion 122 is provided so as to be wider in the X-axis direction than the crystal base portion 121 when viewed in plan.

  The crystal vibrating section 123 is for exciting vibration of a desired frequency by, for example, forming excitation electrodes 125 and 126 of a desired pattern on the surface thereof and applying a potential to the excitation electrodes 125 and 126. . The crystal vibrating section 123 includes a first crystal vibrating section 123a and a second crystal vibrating section 123b. The first crystal vibrating portion 123a and the second crystal vibrating portion 123b extend from one side of the crystal base 121 in parallel with the Y'-axis direction.

  Further, the quartz vibrating portion 123 is provided with a hammerhead-shaped weight portion 129 at the tip thereof, that is, at the end of the quartz vibrating portion 123 opposite to the quartz base 121. The weight part 129 is for adjusting the frequency of the bending vibration generated in the crystal vibrating part 123. Specifically, by providing the weight portion 129, it is possible to approach the state where the weight is provided on the tip side of the crystal vibrating portion 123, and the frequency of the bending vibration generated in the crystal vibrating portion 123 is reduced by the weight portion 129. The frequency can be set lower than in the case, and the frequency of the bending vibration generated in the crystal vibrating section 123 is adjusted to be a desired frequency. The weight portion 129 includes a first weight portion 129a provided at a tip portion of the first crystal vibrating portion 123a and a second weight portion 129b provided at a tip portion of the second crystal vibrating portion 123b. Have been.

  The crystal support portion 124 is for holding and fixing the tuning fork type crystal element 120 on the package 110 together with the crystal holding portion 122 described above. The crystal supporting portion 124 is provided at one end of the crystal holding portion 122 so as to extend in the same direction as the crystal vibrating portion 123 from the surface of the crystal holding portion 122 in the same direction as the surface on which the crystal vibrating portion 123 is formed. ing. That is, the crystal supporting portion 124 extends from one side of the crystal holding portion 122 in parallel with the Y′-axis direction. Further, the crystal supporting portion 124 is provided so as to be located outside the crystal vibrating portion 123. Such a tuning fork type crystal element 120 has a tuning fork shape integrally with a crystal base 121, a crystal holding part 122, each crystal vibrating part 123 and a crystal supporting part 124, and is formed by photolithography technology and chemical etching technology. Manufactured.

  The first groove portion D1 can rapidly attenuate the state of vibration between the crystal vibrating portion 123 and the crystal holding portion 122 and reduce vibration leakage from the crystal vibrating portion 123 to the crystal holding portion 122. It is. The first groove portion D1 is provided on the upper surface and the lower surface of the crystal holding portion 122 from one side constituting the side surface at a position facing the side surface on which the crystal vibrating portion 123 is formed toward the crystal base portion 121. The first groove D1 includes one first groove D1a and the other first groove D1b. By providing the first groove portion D1 in the crystal holding portion 122 in this manner, the state of vibration between the crystal vibrating portion 123 and the crystal holding portion 122 can be rapidly attenuated. Vibration leakage to the motor 122 can be reduced.

  Further, since the first groove D1 is formed by etching, an etching residue is generated in the first groove D1. Thus, the mounting is performed by generating the etching residue in the first groove D1. Can be gradually alleviated in the etching residue portion, and the influence on the crystal vibrating portion 112 can be reduced.

  In addition, when the crystal holding unit 122 is viewed in a plan view, the extraction electrode 127 is provided at an end of the crystal holding unit 122 so as to be located outside the first groove portion D1. That is, when the tuning-fork type crystal element 120 is viewed in a plan view, the extraction electrode is provided on at least one of both ends of the crystal holding part 122, and one first groove D1a and the other first groove D1b are It is provided so as to be located inside both ends of the crystal holding part 122. When the extraction electrode 127 of the tuning fork type crystal element 120 is mounted as a fixed portion, the vibration transmitted from the crystal vibrating portion 123 is blocked by the first groove D1 provided in the crystal holding portion 122, and thus the crystal vibrating portion 123 The state of the vibration between the crystal holding portion 122 and the crystal holding portion 122 can be rapidly attenuated, the vibration leakage from the crystal vibrating portion 123 to the crystal holding portion 122 is reduced, and the crystal holding portion 122 comes into contact with the electrode pad 111. It is possible to reduce the inhibition of vibration from the portion where the vibration occurs to the crystal vibrating portion 123.

  When the crystal holding portion 122 is viewed in plan, the length of one of the first grooves D1a in the extending direction of the crystal vibrating portion 123 is equal to the other first groove D1b when viewing the crystal holding portion 122 in plan. Is provided to be shorter than the length of the crystal vibrating portion 123 in the extending direction. The length of one of the first grooves D1a in the Y′-axis direction is 15 to 30 μm, and the length in the X-axis direction is 20 to 40 μm. The length of the other first groove portion D1b in the Y′-axis direction is 30 to 50 μm, and the length in the X-axis direction is 20 to 40 μm. As described above, when the length of the crystal vibrating portion 123 in the other first groove portion D1b in the extending direction is the planar direction of the crystal holding portion 122, the extending direction of the crystal vibrating portion 123 in the one first groove portion D1a. Is provided so as to be longer than the length of the first vibrating portion D1a, and by making the areas of the etching residue portions formed in the first groove portion D1a and the other first groove portion D1b equal, the influence on the crystal vibrating portion 123 is obtained. Can be alleviated. Further, even if the end of the crystal holding section 122 where the crystal supporting section 124 is not provided is in contact with the electrode pad 111, it is possible to reduce the transmission of vibration from the contacted portion of the crystal holding section 122 to the crystal vibrating section 123. can do.

  The convex portion B is provided on a side surface of the crystal supporting portion 124 parallel to the direction in which the crystal vibrating portion 123 extends. Therefore, the convex portion B extends from the side surface of the crystal supporting portion 124 parallel to the Y ′ axis and the Z ′ axis. By doing so, when the tuning-fork type crystal element 120 is viewed in a plan view, the length of the crystal support portion 124 in the direction perpendicular to the direction in which the crystal support portion 124 extends (the direction parallel to the X axis) is: Only the portion where the protrusion B is provided is longer. Therefore, by providing the convex portion B on the side surface of the crystal support portion 124 parallel to the Y ′ axis and the Z ′ axis, the convex portion B functions as a weight when bending vibration occurs in the crystal support portion 124. As a result, it is possible to reduce the bending vibration in the crystal supporting portion 124. For this reason, in this manner, the bending vibration generated in the crystal supporting portion 124 and the bending vibration generated in the crystal vibrating portion 123 affect each other. Specifically, the bending vibration is deteriorated and the equivalent series resistance is deteriorated. Deterioration of electrical characteristics such as an increase in the value can be reduced.

  Further, a notch C is formed in the protrusion B. The frequency of the bending vibration generated in the crystal vibrating part 123 and the crystal supporting part 124 is related to the length parallel to the Y ′ axis and the length parallel to the X axis. Since the frequency tends to be lower, the frequency of the bending vibration generated in the crystal supporting portion 124 is lower than the frequency of the bending vibration generated in the crystal vibrating portion 123 when the convex portion B is provided on the crystal supporting portion 124. It is to prevent it from becoming. Therefore, when the notch portion C is not formed in the convex portion B, when the bending vibration occurs in the crystal supporting portion 124, the frequency of the bending vibration generated in the crystal supporting portion 124 occurs in the crystal vibrating portion 123. Since the frequency becomes lower than the frequency of the bending vibration, a desired frequency characteristic cannot be obtained, and the electric characteristic may be deteriorated. For this reason, in the tuning fork type crystal element 120, the convex portion B in which the notch portion C is formed is provided in the crystal supporting portion 124.

  The excitation electrodes 125a are provided on the front and back main surfaces of the first crystal vibrating portion 123a, as shown in FIGS. Further, the excitation electrodes 126b are provided on both opposing side surfaces of the first crystal vibrating portion 123a. The frequency adjusting metal film 128a is provided on the front main surface and the end of the side surface of the first crystal vibrating portion 123a. The one extraction electrode 127a is provided near the center of the crystal supporting portion 124, in the crystal holding portion 122, and in a plan view. The other extraction electrode 127b is electrically connected to the excitation electrodes 125a and 126a, and is provided on the front and back main surfaces near the boundary between the crystal support portion 124 and the crystal holding portion 122.

  The excitation electrodes 125b are provided on the front and back main surfaces of the second crystal vibrating portion 123b, as shown in FIGS. Further, the excitation electrodes 126a are provided on both opposing side surfaces of the second crystal vibrating portion 123b. The frequency adjusting metal film 128b is provided on the front main surface and the front end portions of both side surfaces of the second crystal vibrating portion 123b. The other extraction electrode 127b is electrically connected to the excitation electrodes 125b and 125b, and is provided on the front and back main surfaces of the crystal holding unit 122 and the crystal supporting unit 124. The other extraction electrode 127b is provided so as to extend from the crystal base 121 and the crystal holder 122 to the crystal support 124.

  The frequency value of the tuning-fork type crystal element 120 can be adjusted to a desired value by increasing or decreasing the amount of metal constituting the frequency adjusting metal films 128a and 128b. As shown in FIG. 3, the excitation electrodes 125b and 126b and the frequency adjusting metal film 128a are electrically connected to each other by an extraction electrode 127a provided on the surface of the crystal support portion 124 or the crystal holding portion 122. Further, the excitation electrodes 125a and 126a and the metal film 128b for frequency adjustment are electrically connected by the extraction electrode 127b provided on the surface of the crystal holding part 122 and the crystal supporting part 125.

  When vibrating the tuning-fork type crystal element 120, an alternating voltage is applied to the extraction electrodes 127a and 127b. When a certain electrical state after the application is instantaneously captured, the excitation electrode 126b of the second quartz-crystal vibrating portion 123b becomes a + (plus) potential, the excitation electrode 126a becomes a-(minus) potential, and an electric field is generated from + to-. . On the other hand, the polarity of the excitation electrode 126 of the first crystal vibrating portion 123a at this time is opposite to the polarity generated on the excitation electrode 126 of the second crystal vibrating portion 123b. Due to these applied electric fields, the first crystal vibrating portion 123a and the second crystal vibrating portion 123b expand and contract, and a bending vibration having the resonance frequency set for each crystal vibrating portion 123 is obtained.

  The long side dimension when the crystal blank is viewed in a plan view is 0.8 to 1.2 mm, and the short side dimension when viewed in a plan view is 0.2 to 0.7 mm. The crystal holding unit 122, the crystal vibrating unit 123, and the crystal support unit 124 will be described. The long side dimension when the crystal base 121 is viewed in plan is 0.2 to 0.4 mm, and the short side dimension when viewed in plan is 0.1 to 0.3 mm. The long side dimension of the crystal holding unit 122 when viewed in plan is 0.2 to 0.7 mm, and the short side dimension when viewed in plan is 0.03 to 0.12 mm. The long side dimension of the crystal vibrating portion 123 when viewed in plan is 0.6 to 0.9 mm, and the short side dimension when viewed in plan is 0.05 to 0.2 mm. The long side dimension of the crystal supporting portion 124 when viewed in plan is 0.6 to 0.9 mm, and the short side dimension when viewed in plan is 0.05 to 0.2 mm.

  Here, the operation of the tuning fork type crystal element 120 will be described. When an external alternating voltage is applied from the extraction electrode 127 to the crystal vibrating section 123 via the excitation electrodes 125 and 126, the tuning fork crystal element 120 causes the crystal vibrating section 123 to excite in a predetermined vibration mode and frequency. It has become.

  Here, a method for manufacturing the tuning fork type crystal element 120 will be described. First, a wafer from which a large number of tuning fork type crystal elements 120 are obtained is cut out of crystal. By etching the upper and lower surfaces of the wafer through an etching mask made of a resist, a crystal blank having a crystal base 121, a crystal holder 122, a crystal oscillator 123, and a crystal support 124 is formed. Further, by forming a conductive layer on the crystal blank through a mask, the excitation electrodes 125 and 126 and the extraction electrode 127 are formed. Note that the formation of the conductive layer may be performed in a wafer state or may be performed after singulation.

  The first groove portion D1 is formed by, for example, etching for forming the crystal base portion 121, the crystal holding portion 122, the crystal vibrating portion 123, and the crystal support portion 124, or by another etching. Here, even if the first groove portion D1 is formed at the same time as the etching for forming the crystal base 121, the crystal holding portion 122, the crystal vibrating portion 123, and the crystal supporting portion 124, like the gap between the pair of crystal vibrating portions 123. Instead of forming a through hole, the concave portion is formed by the fact that the crystal exhibits anisotropy derived from the crystal with respect to the etching, and the diameter of the opening for forming the first groove portion D1 of the etching mask is relatively small. That's because. When the tuning-fork type crystal element 120 is cut off from the crystal wafer, the first groove D1 is provided in the vicinity of the connection T as shown in FIG. , It is possible to reduce the possibility of occurrence of burrs.

  The tuning-fork type crystal element 120 according to the first embodiment opposes a substantially rectangular crystal base 121, a crystal vibrating part 123 provided to extend from a side surface of the crystal base 121, and a side surface of the crystal base 121. A substantially rectangular crystal holding portion 122 provided to extend from the side surface at the position, and one crystal provided to extend from the side surface of the crystal holding portion 122 in the same direction as the crystal vibrating portion 123. A pair of first groove portions D <b> 1 provided on the upper surface and the lower surface of the crystal holding portion 122 from one side constituting the side surface at a position facing the side surface on which the crystal vibrating portion 123 is formed, to the support portion 124 and the crystal vibrating portion 123. Excitation electrodes 125 and 126 provided on the upper and lower surfaces of the crystal vibrating section 123, and excitation electrodes 125 provided from the crystal vibrating section 123 to the crystal base 121 and the crystal supporting section 124. And 126 and electrically connected to the extraction electrode 127, and a.

  In such a tuning-fork type crystal element 120, when the first groove portion D1 is provided in the crystal holding portion 122 in plan view, the vibration is blocked by the first groove portion D1. The state of the vibration with the part 122 can be rapidly attenuated, the vibration leakage from the crystal vibrating part 123 to the crystal holding part 122 is reduced, and the vibration from the part in contact with the crystal vibrating part 123 is inhibited. Can be reduced. Therefore, the tuning fork type crystal element 120 can improve electrical characteristics.

  The tuning fork type crystal element 120 according to the first embodiment is configured such that, when the crystal holding part 122 is viewed in a plan view, the length of one first groove D1a is shorter than the length of the other first groove D1b. Is provided. By doing so, the area of the etching residue portion formed in one first groove portion D1a and the other first groove portion D1b is made equal, whereby the influence on the crystal vibrating portion 123 can be reduced. Further, even if the end of the crystal holding section 122 where the crystal supporting section 124 is not provided is in contact with the electrode pad 111, it is possible to reduce the transmission of vibration from the contacted portion of the crystal holding section 122 to the crystal vibrating section 123. can do.

  The tuning-fork type crystal element 120 according to the first embodiment has an end portion of the crystal holding portion 122 such that the extraction electrode 127 is located outside the first groove portion D1 when the crystal holding portion 122 is viewed in a plan view. It is provided in. When mounting such a tuning-fork type crystal element 120, the vibration transmitted from the crystal vibrating section 123 is blocked by the first groove D <b> 1 provided in the crystal holding section 122. Can be rapidly attenuated, the vibration leakage from the crystal vibrating portion 123 to the crystal holding portion 122 can be reduced, and the crystal vibrating portion can be reduced from the portion where the crystal holding portion 122 is in contact with the electrode pad 111. This makes it possible to reduce the inhibition of vibration of the motor 123.

(First modification)
Hereinafter, the tuning fork type crystal element 120 according to the first modified example of the first embodiment will be described. Note that, of the tuning fork-type crystal element in the first modification of the first embodiment, the same portions as those of the above-described tuning fork-type crystal element are denoted by the same reference numerals, and description thereof will be omitted as appropriate. As shown in FIG. 4, the tuning fork type crystal element 120 according to the first modification of the first embodiment includes a second groove D2 provided in a crystal vibrating part 123, and an excitation electrode 125 is provided in the second groove D2. And a projection P provided in the second groove D2.

  The second groove portion D2 is formed, for example, by forming an excitation electrode 125 having a desired pattern on the surface inside the second groove portion D2 and applying a potential to the electrode. It is used to obtain a larger electric field strength. The second groove D2 includes one second groove D2a and the other second groove D2b. One second groove portion D2a is provided on each of the front and back main surfaces of the first crystal vibrating portion 123a, and is parallel to the longitudinal direction of the first crystal vibrating portion 123a. Are provided so as to face each other. One end of one second groove D2a is provided at a boundary between the first crystal vibrating portion 123a and the base 121, and the other end of one second groove D2a is provided with a first crystal vibrating portion. It is provided to be located on the tip side of 123a. The other second groove portion D2b is provided on each of the front and back main surfaces of the second crystal vibrating portion 123b in parallel with the longitudinal direction of the second crystal vibrating portion 123b. They are provided to face each other on the main surface. One end of the other second groove D2b is provided at a boundary between the second crystal vibrating portion 123b and the crystal base 121, and the other end of the other second groove D2b is provided with a second crystal vibrating portion. It is provided so as to be located on the tip side of the portion 123b. The length of the second groove portion D2 is, for example, 50 to 80% of the length of the first crystal vibrating portion 123a and the second crystal vibrating portion 123b.

  When the second groove D2 is formed by etching, the projection P simultaneously forms the outer shape of the tuning fork type crystal element 120 and the second groove D2 due to a difference in etching rate depending on the crystal orientation due to the etching anisotropy of the quartz crystal. It is for doing. The projection P includes a plurality of first projections P1 provided in one second groove D2a and a plurality of second projections P2 provided in the other second groove D2b. I have. A plurality of projections P are provided at equal intervals so as to extend in the X'-axis direction from the lengthwise side surface on the + X-axis side to the lengthwise side surface on the -X-axis side in the second groove portion D2. I have. The protrusion dimension of the protrusion P varies depending on the width of the second groove D2, and is about 0.005 to 0.015 mm when viewed in the length in the −X ′ direction.

  In each of the above-described embodiments, the protrusions P are provided at equal intervals in the second grooves D2. However, depending on the size of the tuning-fork type crystal element 120, the distance between the protrusions P may be reduced. I try to be different. By making the intervals between the projections P different from each other, the projections P provided in the second grooves D2 formed on the front and back surfaces of the crystal vibrating portion 123 are heavy when the projections P are seen through the plane. It can be placed in a position where it is not necessary. Therefore, it is possible to reduce the penetration of the second groove D2 when the second groove D2 is formed by etching.

  Further, by providing the projection P, when the second groove D2 is formed by etching, the outer shape of the tuning-fork type crystal element 120 and the second The groove D2 can be formed simultaneously by etching. Therefore, the productivity of the tuning fork type crystal element 120 can be improved.

(Second modification)
Hereinafter, the tuning fork type crystal element 120 according to the second modification of the first embodiment will be described. In the tuning fork-type crystal element according to the second modification of the first embodiment, the same parts as those of the above-described tuning fork-type crystal element are denoted by the same reference numerals, and description thereof will not be repeated. The tuning fork type crystal element 120 according to the second modification of the first embodiment has a point that the number of the second grooves D2 is two for one crystal vibrating part 123 as shown in FIG. Is different.

  Further, the second grooves D2a, D2b, D2c and D2d are constituted by a total of four, two for each crystal vibrating part 123. The second groove portions D2a and D2b are respectively provided on the front and back main surfaces of the first crystal vibrating portion 123a, respectively, in parallel with the longitudinal direction of the first crystal vibrating portion 123a, and the front and back main surfaces of the first crystal vibrating portion 123a. Are provided so as to face each other. One end of each of the second grooves D2a and D2b is provided at a boundary between the first crystal vibrating part 123a and the base 121, and the other end of the second grooves D2a and D2b is provided with the first crystal vibrating part. It is provided to be located on the tip side of 123a. In addition, the second grooves D2c and D2d are respectively provided on the front and back main surfaces of the second crystal vibrating portion 123b, respectively, in parallel with the longitudinal direction of the second crystal vibrating portion 123b, and on both sides of the second crystal vibrating portion 123b. They are provided to face each other on the main surface. One end of each of the second grooves D2c and D2d is provided at a boundary between the second crystal vibrating portion 123b and the base 121, and the other end of the second grooves D2c and D2d is provided with a second crystal vibrating portion. It is provided so as to be located on the tip side of 123b. In addition, by providing a plurality of second grooves D2, by applying a potential to the excitation electrodes 125 and 126 provided in the second grooves D2, the crystal is more crystallized than in the case where only one second groove D2 is provided. The distance between the excitation electrodes 125 and 126 provided on the upper surface, the lower surface, and the side surface of the vibration section 123 can be shortened, and the crystal impedance can be reduced. Further, at this time, by etching the crystal vibrating portion 123 largely, the strength of the crystal vibrating portion 123 is reduced and the impact resistance is reduced, but this is combined with the configuration of holding the crystal vibrating portion 123 and the crystal supporting portion 124. The shock can be absorbed, and the shock resistance of the tuning fork type crystal element 120 can be improved.

(Second embodiment)
As shown in FIGS. 6 to 9, the crystal device of the second embodiment includes a package 110 and the tuning-fork type crystal element 120 of the first embodiment mounted on the upper surface of the package 110. The package 110 has a concave portion K surrounded by the upper surface of the substrate 110a and the inner surface of the frame 110b. Such a crystal device is used to output a reference signal used in electronic equipment and the like.

  The substrate 110a has a rectangular shape and functions as a mounting member for mounting the tuning-fork type crystal element 120 on the upper surface. On the upper surface of the substrate 110a, an electrode pad 111 for mounting the tuning-fork type crystal element 120 is provided. Further, a first electrode pad 111a and a second electrode pad 111b for joining the tuning fork type crystal element 120 are provided along one long side of the substrate 110a.

  The substrate 110a is made of an insulating layer made of a ceramic material such as alumina ceramic or glass-ceramic. The substrate 110a may be one having a single insulating layer or one having a plurality of insulating layers stacked. A wiring pattern 113 and a via conductor 114 for electrically connecting the electrode pads 111 provided on the upper surface and the external terminals 112 provided on the lower surface of the substrate 110a are provided on the surface and inside of the substrate 110a. I have.

  The frame 110b is arranged along the outer peripheral edge of the upper surface of the substrate 110a, and is for forming the concave portion K on the upper surface of the substrate 110a. The frame 110b is made of a ceramic material such as alumina ceramics or glass-ceramics, and is formed integrally with the substrate 110a. The opening of the concave portion K has a rectangular shape when viewed in plan.

  External terminals 112 are provided at four corners on the lower surface of the substrate 110a. Two of the four external terminals 112 are electrically connected to the tuning-fork type crystal element 120. Further, the first external terminal 112a and the second external terminal 112b that are electrically connected to the tuning fork type crystal element 120 are provided so as to be located diagonally on the lower surface of the substrate 110a.

  The electrode pad 111 is for mounting the tuning-fork type crystal element 120. The electrode pads 111 are provided as a pair on the upper surface of the substrate 110a, and are provided adjacent to each other along one side of the substrate 110a. The electrode pad 111 is electrically connected to the external terminal 112 provided on the lower surface of the substrate 110a via the wiring pattern 113 and the via conductor 114 provided on the upper surface of the substrate 110a as shown in FIGS. It is connected to the.

  As shown in FIG. 8, the electrode pad 111 includes a first electrode pad 111a and a second electrode pad 111b. The external terminal 112 includes a first external terminal 112a, a second external terminal 112b, a third external terminal 112c, and a fourth external terminal 112d, as shown in FIG. As shown in FIGS. 8 and 9, the via conductor 114 includes a first via conductor 114a, a second via conductor 114b, and a third via conductor 114c. The wiring pattern 113 includes a first wiring pattern 113a and a second wiring pattern 113b. The first electrode pad 111a is electrically connected to one end of a first wiring pattern 113a provided on the substrate 110a. The other end of the first wiring pattern 113a is electrically connected to the first external terminal 112a via the first via conductor 114a. Therefore, the first electrode pad 111a is electrically connected to the first external terminal 112a. The second electrode pad 111b is electrically connected to one end of a second wiring pattern 113b provided on the substrate 110a. The other end of the second wiring pattern 113b is electrically connected to the second external terminal 112b via the second via conductor 114b. Therefore, the second electrode pad 111b is electrically connected to the second external terminal 112b.

  The arithmetic average surface roughness of the electrode pad 111 is 0.02 to 0.10 μm, and the arithmetic average surface roughness of the surface of the substrate 110a is 0.5 to 1.5 μm. Therefore, the conductive adhesive 140 is unlikely to spread from the electrode pad 111 onto the substrate 110a.

  The external terminals 112 are used to electrically connect to a mounting board (not shown) of an electronic device or the like. The external terminals 112 are provided at four corners on the lower surface of the substrate 110a. Two of the external terminals 112 are electrically connected to a pair of electrode pads 111 provided on the upper surface of the substrate 110a. The third external terminal 112c is electrically connected to the sealing conductor pattern 117 via the third via conductor 114c.

  The first wiring pattern 113a is electrically connected to the first electrode pad 111a and the first via conductor 114a. The first wiring pattern 113a is drawn out from the first electrode pad 111a, and a part of the first wiring pattern 113a is exposed on the upper surface of the substrate 110a. The second wiring pattern 113b is electrically connected to the second electrode pad 111b and the second via conductor 114b. The second wiring pattern 113b extends from the second electrode pad 111b toward the short side of the frame 110b, and a part of the second wiring pattern 113b is exposed.

  The via conductor 114 is provided inside the substrate 110a, and both ends thereof are electrically connected to the wiring pattern 113 or the sealing conductor pattern 117. The via conductor 114 is provided by filling the inside of a through hole provided in the substrate 110a with a conductor. 8 and 9, the via conductor 114 includes a first via conductor 114a, a second via conductor 114b, and a third via conductor 114c.

  Here, a case where the dimension of one side when the package 110 is viewed in a plan view is 1.0 to 3.0 mm and the vertical dimension of the package 110 is 0.2 to 1.5 mm is described as an example. K, the size of the electrode pad 111 and the size of the protrusion 115 will be described. The length of the long side of the concave portion K is 0.7 to 2.0. mm, and the length of the short side is 0.5 to 1.5 mm. The length of the concave portion K in the vertical direction is 0.1 to 0.5 mm. The length of the side of the electrode pad 111 parallel to one side of the substrate 110a is 0.25 to 0.40 mm. The length of the side of the electrode pad 111 that is parallel to the side intersecting with one side of the substrate 110a is 0.25 to 0.40 mm. The vertical length of the electrode pad 111 is 10 to 50 μm.

  The sealing conductor pattern 117 plays a role of improving the wettability of the joining member 131 when joining with the lid 130 via the joining member 131. The sealing conductor pattern 117 is provided so as to surround the upper surface of the frame 110b. As shown in FIGS. 2 and 4, the sealing conductor pattern 117 is electrically connected to the third external terminal 112c via the third via conductor 114c. The sealing conductor pattern 117 is formed to a thickness of, for example, 10 to 25 μm by sequentially applying nickel plating and gold plating to the surface of the conductor pattern made of, for example, tungsten, molybdenum, or the like so as to annularly surround the upper surface of the frame 110b. Have been.

  Here, a method for manufacturing the substrate 110a is described. When the substrate 110a is made of alumina ceramic, first, a plurality of ceramic green sheets obtained by adding and mixing an appropriate organic solvent or the like to a predetermined ceramic material powder are prepared. Further, a predetermined conductor paste is applied to the surface of the ceramic green sheet or a through hole formed by punching the ceramic green sheet or the like in advance by screen printing or the like known in the art. Further, those green sheets laminated and press-molded are fired at a high temperature. Finally, a predetermined portion of the conductor pattern, specifically, a portion to be the electrode pad 111, the external terminal 112, the wiring pattern 113, the via conductor 114, the convex portion 115, and the sealing conductor pattern 117, is nickel-plated or gold-plated. It is produced by applying silver palladium or the like. The conductive paste is made of, for example, a sintered body of a metal powder such as tungsten, molybdenum, copper, silver, or silver palladium.

  A method of joining the tuning fork type crystal element 120 to the substrate 110a will be described. First, the conductive adhesive 140 is applied to the upper surfaces of the pair of electrode pads 111 by, for example, a dispenser. The tuning fork type crystal element 120 is conveyed onto the conductive adhesive 140 and mounted on the conductive adhesive 140. The tuning fork type crystal element 120 is joined to the pair of electrode pads 111 by heating and curing the conductive adhesive 140.

  The conductive adhesive 140 is provided on the electrode pad 111 facing the extraction electrodes 127a and 127b, and is provided so as to fix one end of the tuning-fork type crystal element 120 to the upper surface of the substrate 110a. In addition, the conductive adhesive 140 expands when heat is applied to the crystal device, and contracts when cooled. When the conductive adhesive 140 thermally expands and contracts, a stress is applied to the tuning-fork type crystal element 120. The stress caused by the conductive adhesive 140 isotropically distributed so as to be concentric. As described above, the stress generated by the thermal expansion of the conductive adhesive 140 does not spread concentrically, and the space between the crystal supporting portion 124 and the crystal vibrating portion 123 and the first groove portion provided in the crystal holding portion 122 are provided. It will be blocked by D1. Even if the stress caused by the conductive adhesive 140 propagates, the stress propagates along the edge of the crystal base 121 from the crystal support portion 124. By doing so, the distance until the stress of the conductive adhesive 140 propagates to the excitation electrodes 125 and 126 can be increased, so that the stress of the conductive adhesive 140 propagates to the excitation electrodes 125 and 126. Before can be relaxed enough. Therefore, the influence of the stress of the conductive adhesive 140 on the excitation electrodes 125 and 126 can be reduced.

  The conductive adhesive 140 contains a conductive powder as a conductive filler in a binder such as a silicone resin. As the conductive powder, one containing any of aluminum, molybdenum, tungsten, platinum, palladium, silver, titanium, nickel, or nickel iron, or a combination thereof is used. As the binder, for example, a silicone resin, an epoxy resin, a polyimide resin, or a bismaleimide resin is used.

  The use of the conductive adhesive 140 having a viscosity of 35 to 45 Pa · s makes it difficult for the conductive adhesive 140 to flow out of the electrode pad 111 to the upper surface of the substrate 110 a when applied. 111, and the vertical thickness is maintained. The length of the conductive adhesive 140 in the vertical direction is 10 to 25 μm. Since the thickness of the conductive adhesive 140 can be secured in this manner, even if an impact applied by a test such as a drop is applied to the tuning fork type crystal element 120 in the vertical direction around the conductive adhesive 140, The impact can be sufficiently absorbed and reduced by the conductive adhesive 140.

  The lid 130 is made of, for example, an alloy containing at least one of iron, nickel, and cobalt. Such a lid 130 is for hermetically sealing the concave portion K in a vacuum state or the concave portion K filled with nitrogen gas or the like. Specifically, the lid 130 is placed on the frame 110b of the package 110 in a predetermined atmosphere. Then, by applying a predetermined current to the lid 130 and performing seam welding so that the sealing conductor pattern 117 of the frame 110b and the joining member 131 of the lid 130 are welded, the lid 130 is framed. Join to the body 110b.

  The joining member 131 is provided at a location of the lid 130 opposite to the sealing conductor pattern 117 provided on the upper surface of the frame 110b of the package 110. The joining member 131 is provided by, for example, gold tin or silver brazing. In the case of gold tin, the thickness is 10 to 40 μm. For example, those having a component ratio of 78 to 82% for gold and 18 to 22% for tin are used. In the case of silver brazing, its thickness is 10 to 20 μm. For example, as the component ratio, silver having a content of 72 to 85% and copper having a content of 15 to 28% is used.

  For example, in the case of glass, the joining member 131 is made of a low-melting glass containing, for example, vanadium, which is a lead-free glass that melts at 350 ° C. to 400 ° C. The lead-free glass is in the form of a paste in which a binder and a solvent are added, and is adhered to other members by being solidified after being melted. The joining member 131 is provided, for example, by applying and drying a glass frit paste by a screen printing method.

  Further, in the crystal device of the second embodiment, by using such a tuning fork type crystal element 120, the crystal support portion 124 on which the lead electrodes 127 a and 127 b which are fixed with the conductive adhesive 140 are formed. The propagation of the stress to the excitation electrodes 125 and 126 generated by the conductive adhesive 140 by being blocked by the space between the crystal vibrating portion 123 and the first groove D1 provided in the crystal holding portion 122. become. Further, even if the stress caused by the conductive adhesive 140 propagates, the stress propagates along the crystal support 124 and the crystal base 121. By doing so, the distance until the stress propagates to the excitation electrodes 125 and 126 can be increased, so that the stress can be sufficiently reduced before the stress propagates to the excitation electrodes 125 and 126. Therefore, it is possible to reduce the crystal impedance value of the tuning fork type crystal element 120 while suppressing the bending vibration of the tuning fork type crystal element 120 from being hindered.

  In the crystal device of the second embodiment, the wiring pattern 113 is electrically connected to the electrode pad 111, and is provided at a position overlapping the frame 110b when viewed in a plan view. By doing so, the crystal device suppresses the generation of stray capacitance between the wiring pattern 113 and the tuning fork type crystal element 120, so that the stray capacitance is not applied to the tuning fork type crystal element 120. Therefore, fluctuation of the oscillation frequency can be suppressed. Further, even if an external force is applied to the quartz crystal device and a bending moment is generated in the long side direction of the frame 110b, the location where the frame 110b is provided is provided by the provision of the frame 110b in addition to the substrate 110a. Is less likely to deform. Therefore, the wiring pattern 113 provided at a position overlapping the frame 110b in a plan view is less likely to be disconnected, and can prevent the oscillation frequency from being output.

(First modification)
Hereinafter, a crystal device according to a first modification of the second embodiment will be described. Note that, in the crystal device according to the first modification of the second embodiment, the same portions as those of the above-described crystal device are denoted by the same reference numerals, and description thereof will be omitted as appropriate. The crystal device according to the first modification of the second embodiment is different from the crystal device according to the first embodiment in that a convex portion 115 is provided on the upper surface of a substrate 110a, as shown in FIGS.

  The convex portion 115 is for suppressing the vertical inclination of the short side of the tuning fork type crystal element 120 and for suppressing the long side end of the tuning fork type crystal element 120 from contacting the substrate 110 a or the lid 130. It is. As shown in FIGS. 10 and 11, the convex portion 115 is provided on the upper surface of the substrate 110a along one side of the substrate 110a at a position facing the one side of the substrate 110a at the position where the second electrode pad 111b is close. Have been. Similarly to the electrode pad 111, the convex portion 115 is provided by applying gold plating or nickel plating on the upper surface of a sintered body of a metal powder such as tungsten, molybdenum, copper, silver, or silver palladium. The convex portion 115 is provided at a position overlapping with a crystal holding portion 122 of a tuning-fork type crystal element 120 described later in plan view. By doing so, it is possible to prevent the crystal base 121 from contacting the substrate 110a when mounting the tuning fork type crystal element 120. The length of the side of the protrusion 115 that is parallel to one side of the substrate 110a is 0.05 to 0.15 mm. In addition, the length of the side of the convex portion 115 that is parallel to the side intersecting with one side of the substrate 110a is 0.20 to 0.35 mm. The length in the vertical direction of the protrusion 115 is 17 to 65 μm.

  Further, the crystal device according to the first modification of the second embodiment is configured such that the crystal vibrating portion 123 of the tuning-fork type crystal element 120 comes into contact with the substrate 110a because the crystal base 121 is in contact with the convex portion 115. Can be suppressed. Therefore, it is possible to prevent the crystal vibrating portion 123 of the tuning fork type crystal element 120 from contacting the substrate 110a, so that it is possible to reduce the fluctuation of the oscillation frequency of the tuning fork type crystal element 120.

  In the crystal device according to the first modification of the second embodiment, the thickness of the protrusion 115 in the vertical direction is provided to be larger than the thickness of the electrode pad 111 in the vertical direction. By doing so, the contact of the crystal base 122 of the tuning-fork type crystal element 120 with the substrate 110a can be further suppressed. Therefore, the contact of the crystal vibrating portion 123 of the tuning-fork type crystal element 120 with the substrate 110a can be further suppressed, so that the fluctuation of the oscillation frequency of the tuning fork-type crystal element 120 can be further reduced.

(Second modification)
Hereinafter, a crystal device according to a second modification of the second embodiment will be described. Note that, in the crystal device according to the second modification of the second embodiment, the same portions as those of the above-described crystal device are denoted by the same reference numerals, and description thereof will be appropriately omitted. As shown in FIG. 12, the quartz crystal device according to the second modification of the second embodiment is different from the first electrode pad 111a provided so as to be adjacent to the second electrode pad 111b along one side of the substrate 110a. The difference is that a pillow portion 116 is provided.

  The pillow portion 116 is for suppressing the vertical inclination of the short side of the tuning fork type crystal element 120 and suppressing the long side end of the tuning fork type crystal element 120 from contacting the substrate 110 a or the lid 130. It is. The pillow portion 116 is provided on the upper surface of the substrate 110a along one side of the substrate 110a located at a position facing the one side of the substrate 110a located adjacent to the second electrode pad 111b. Similarly to the electrode pad 111, the pillow portion 116 is provided by applying gold plating or nickel plating on the upper surface of a sintered body of a metal powder such as tungsten, molybdenum, copper, silver or silver palladium. The pillow portion 116 is provided at a position overlapping the crystal base portion 121 or the crystal holding portion 122 of the tuning-fork type crystal element 120 to be described later in plan view. By doing so, it is possible to prevent the crystal base 121 or the crystal holding part 122 from contacting the substrate 110a when the tuning fork type crystal element 120 is mounted.

  The crystal device according to the second modification of the second embodiment has the same effect as the crystal device of the second embodiment. In the crystal device according to the second modification of the second embodiment, the pillow portion 116 is provided at a position overlapping the crystal holding portion 122 of the tuning-fork type crystal element 120 in plan view. By doing so, when mounting the tuning fork type crystal element 120, the tuning fork type crystal element 120 is prevented from being inclined and mounted, and the crystal base 121 or the crystal vibrating part 123 is prevented from contacting the substrate 110a. be able to.

  It should be noted that the present invention is not limited to the present embodiment, and various changes and improvements can be made without departing from the spirit of the present invention. In the above-described embodiment, the case where the frame 110b is integrally formed of a ceramic material similarly to the substrate 110a has been described, but the frame 110b may be made of metal. In this case, the frame is joined to the conductor film of the substrate via a brazing material such as silver-copper.

  In the second embodiment, the case where four external terminals 112 are provided on the lower surface of the substrate 110a has been described, but two external terminals may be provided on the lower surface of the substrate. In this case, the sealing conductor pattern is not electrically connected to the external terminal.

110 ... package 110a ... substrate 110b ... frame 111 ... electrode pad 112 ... external terminal 113 ... wiring pattern 114 ... via conductor 115 ... convex part 116 ... Pillow part 117: Sealing conductor pattern 120: Tuning fork type crystal element 121: Crystal base 122: Crystal holding part 123: Crystal vibrating part 124: Crystal supporting parts 125, 126 ..Exciting electrode 127 ... Extraction electrode 128 ... Metal film for frequency adjustment 129 ... Plummet 130 ... Lid 131 ... Joining member 140 ... Conductive adhesive B ... Convex Part C: Notch part D1: First groove part D2: Second groove part K: Recess P: Projection part

Claims (6)

A substantially rectangular crystal base,
A crystal vibrating portion provided to extend from a side surface of the crystal base portion,
A substantially rectangular crystal holding portion provided so as to extend from a side surface at a position facing the side surface of the crystal base portion,
One crystal supporting portion provided to extend in the same direction as the crystal vibrating portion from the side surface of the crystal holding portion,
A pair of first grooves provided on the upper surface and the lower surface of the crystal holding portion from one side constituting the side surface at a position opposed to the side surface on which the crystal vibrating portion is formed,
Excitation electrodes provided on the upper surface, the lower surface, and the side surfaces of the quartz vibrating portion,
A lead electrode provided from the crystal vibrating portion to the crystal base portion , the crystal holding portion and the crystal support portion, and electrically connected to the excitation electrode ;
When the first groove portion is a plan view of the crystal holding portion,
The length of the first groove portion in the extending direction of the crystal vibrating portion is provided so as to be shorter than the length of the other first groove portion in the extending direction of the crystal vibrating portion. Tuning fork type crystal element. The tuning fork type crystal element according to claim 1,
When the crystal holding unit is viewed in plan,
A tuning-fork type crystal element, wherein the extraction electrode is provided at an end of the crystal holding portion so as to be located closer to an end of the crystal holding portion than the first groove portion. The tuning fork-type crystal element according to claim 1 or 2 ,
Comprising a second groove portion provided in the crystal vibrating portion,
A tuning fork-type crystal element, wherein the excitation electrode is provided in the second groove. The tuning fork type crystal element according to claim 3 , wherein
A tuning fork-type crystal element, comprising: a projection provided in the second groove. A tuning-fork type crystal element according to any one of claims 1 to 4 ,
Is composed of a board and the frame, and a package having an electrode pad provided on a surface of the substrate,
A lid for hermetically sealing the tuning-fork type crystal element. The crystal device according to claim 5 , wherein
A quartz device, comprising: a convex portion on an upper surface of the substrate, the convex portion having a vertical thickness greater than a vertical thickness of the electrode pad.

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