JP6659288B2 - 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 water tuning fork type crystal element, the downsizing of the crystal device is required to reduce the size of the tuning fork type crystal element. Due to the miniaturization of the tuning fork element, the distance between the vibrating arm of the tuning fork type crystal element and the portion held by the conductive adhesive is shortened, the vibration of the vibrating arm is hindered, and the electrical characteristics are reduced. There is a possibility that it will end up.

  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 embodiment of the present invention defines an XY′Z ′ orthogonal coordinate system on a crystal axis, and has a substantially rectangular crystal base having a thickness in a direction along the Z ′ axis; A crystal vibrating portion provided to extend from the side surface in the + Y'-axis direction, and a crystal vibrating portion provided to extend in the + X-axis direction and the -X-axis direction from a side surface of the crystal base portion facing the side surface. And a single crystal provided so as to extend only in a side surface of the crystal holding portion on the + X axis direction side in the + Y ′ axis direction which is the same direction as the crystal vibrating portion. A supporting portion, which is located between the crystal holding portion and the crystal vibrating portion in plan view, and is located at a position facing one side of the + X-axis direction side of the crystal base portion which is in a position close to the crystal supporting portion; It provided only on one side of the -X-axis direction side of the crystal base Notch portion, excitation electrodes provided on the upper and lower surfaces of the crystal vibrating portion, and a lead-out electrode provided from the crystal vibrating portion to the crystal base portion and the crystal supporting portion and electrically connected to the excitation electrode, It has.

A tuning-fork type crystal element according to one embodiment of the present invention defines an XY′Z ′ orthogonal coordinate system on a crystal axis, and has a substantially rectangular crystal base having a thickness in a direction along the Z ′ axis; A crystal vibrating portion provided to extend from the side surface in the + Y'-axis direction, and a crystal vibrating portion provided to extend in the + X-axis direction and the -X-axis direction from a side surface of the crystal base portion facing the side surface. And a single crystal provided so as to extend only in a side surface of the crystal holding portion on the + X axis direction side in the + Y ′ axis direction which is the same direction as the crystal vibrating portion. A supporting portion, which is located between the crystal holding portion and the crystal vibrating portion in plan view, and is located at a position facing one side of the + X-axis direction side of the crystal base portion which is in a position close to the crystal supporting portion; It provided only on one side of the -X-axis direction side of the crystal base Notch portion, excitation electrodes provided on the upper and lower surfaces of the crystal vibrating portion, and a lead-out electrode provided from the crystal vibrating portion to the crystal base portion and the crystal supporting portion and electrically connected to the excitation electrode, It has. Such a tuning-fork type crystal element is provided between a crystal holding portion and a crystal vibrating portion in plan view, and is provided on one side at a position opposite to one side of a crystal base portion at a position close to the crystal support portion. The vibrating state during this period can be rapidly attenuated by reducing the vibration leakage from the crystal vibrating section to the crystal holding section. Thus, it is possible to reduce the inhibition of vibration to the vibration. 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 lower surface side of the tuning fork crystal element included in the crystal device according to the first embodiment. FIG. (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. (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 3rd modification of 1st Embodiment, (b) The crystal device which concerns on 3rd 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 the plane perspective view which looked at the state where the lid of the crystal device concerning a 2nd embodiment was removed from the upper surface. (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. (A) It is the bottom view which looked at the package which constitutes the crystal device concerning a second embodiment from the lower surface. It is the plane perspective view which looked at the state where the lid of the crystal device concerning a third embodiment was removed from the upper surface.

(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 crystal blank 121, there are formed excitation electrodes 125a, 125b, 126a and 126b, extraction electrodes 127a and 127b, metal films 128a and 128b for frequency adjustment, and a cutout 129.

  The crystal base 121 is used to support a crystal vibrating part 123 and a crystal holding part 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 a package 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.

  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 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. In other words, the crystal support 124 extends from one side of the crystal base 123 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. In such a tuning fork type crystal element 120, a crystal base 121, a crystal holding part 122, each crystal vibrating part 123 and a crystal supporting part 124 are integrally formed in a tuning fork shape, and are formed by photolithography technology and chemical etching technology. Manufactured.

  The tuning fork type crystal element 120 is held or supported by the crystal holding part 122 and the crystal supporting part 124, so that it can be fixed on the substrate 110a with good balance. Therefore, the vibration leakage of the tuning fork type crystal element 120 can be effectively reduced, and the vibration stability can be further improved. Further, by providing the crystal support portion 124, even when an impact is applied to the package 110, which will be described later, on which the tuning-fork type crystal element 120 is mounted by dropping from outside, the impact is applied to the crystal holding portion 122 and the crystal support portion 124. As a result, the shock resistance of the tuning-fork type crystal element 120 can be improved.

  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 127 a is provided near the center of the crystal supporting portion 124 and in the crystal holding portion 122 in 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 notch 129 can attenuate the state of vibration between the crystal vibrating section 123 and the crystal holding section 122 and reduce vibration leakage from the crystal vibrating section 123 to the crystal holding section 122 and the crystal supporting section 124. It is for doing. As shown in FIGS. 1 and 2, the notch portion 129 is located between the crystal holding portion 122 and the crystal vibrating portion 123 in a plan view, and is close to the crystal support portion 124. It is provided on one side at a position facing one side. That is, the notch 129 is provided on the crystal base 121 on which the crystal support 124 is not provided. By providing the notch portion 129 in this manner, the state of vibration between the crystal vibrating portion 123 and the crystal holding portion 122 can be rapidly attenuated. It is possible to reduce the vibration leakage to the part 124 and to reduce the inhibition of vibration from the contacting part to the crystal vibrating part 123. Therefore, such a tuning fork type crystal element 120 can improve electrical characteristics. In addition, since the notch 129 is provided on the crystal base 121 on which the crystal support 124 is not provided, the notch 129 is held by the crystal holder 121 on the short side of the tuning-fork type crystal element 120. In this case, it is possible to reduce the adhesion of a conductive adhesive 140 described later to the crystal vibrating portion 123. In addition, the notch 129 is formed in the direction in which the crystal support 124 is not provided (−X axis), as compared with the direction in which the crystal support 124 is provided (+ X axis). Since the residue generated at 129 becomes large, it is possible to provide a structure having improved strength against external impact.

  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 metal film 128a for frequency adjustment are electrically connected by a lead electrode 127a provided on the surface of the crystal piece. 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, the tuning-fork type crystal element 120 is cut from a synthetic crystal at a predetermined cut angle, and the crystal base 121, the crystal holding section 122, the crystal vibrating section 123, and the crystal supporting section are formed on both main surfaces of the crystal piece 121 by photolithography technology. 124 are formed. Thereafter, a metal film is applied by photolithography, vapor deposition, or sputtering to form the excitation electrodes 125 and 126 and the extraction electrode 127.

  The tuning-fork type crystal element 120 according to the first embodiment has a rectangular crystal base 121, a crystal vibrating part 123 provided to extend from the side surface of the crystal base 121, and a position orthogonal to the side surface of the crystal base 121. A crystal holding portion 122 extending from the side surface of the crystal holding portion 122, and one crystal supporting portion 124 provided to extend from the side surface of the crystal holding portion 122 in the same direction as the crystal vibrating portion 123. A notch 129 provided on one side at a position opposite to one side of the crystal base 121 located between the crystal holding section 122 and the crystal vibrating section 123 and close to the crystal support section 124; The excitation electrodes 125 and 126 provided on the vibrating part 123 and the excitation electrodes 125 and 126 provided from the crystal vibrating part 123 to the crystal base 121, the crystal holding part 122 and the crystal supporting part 124 are electrically connected to each other. And a, and the extraction electrode 127 connected to the.

  Such a tuning-fork type crystal element 120 is located between the crystal holding part 122 and the crystal vibrating part 123 in a plan view, and is located at a position facing one side of the crystal base 121 located at a position close to the crystal supporting part 124. By providing the notch 129 provided on one side, the state of vibration during this period can be rapidly attenuated, and vibration leakage from the crystal vibrating section 123 to the crystal holding section 122 can be reduced, and contact can be reduced. It is possible to reduce the inhibition of vibration from the portion where the vibration occurs to the crystal vibrating portion 123. Therefore, the tuning fork type crystal element 120 can improve electrical characteristics. In addition, the notch 129 is formed in the direction in which the crystal support 124 is not provided (−X axis), as compared with the direction in which the crystal support 124 is provided (+ X axis). Since the residue generated at 129 becomes large, it is possible to provide a structure having improved strength against external impact.

(First modification)
Hereinafter, the tuning fork type crystal element 120 according to the first modification 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. 3, the tuning fork type crystal element 120 according to the first modification of the first embodiment includes a groove D provided in the crystal vibrating section 123, and an excitation electrode 125 is provided in the groove D. And a projection P provided in the groove D.

  For example, by forming the excitation electrode 125 having a desired pattern on the surface in the groove D and applying a potential to the electrode, a greater electric field strength is obtained as compared with the case where the groove D is not provided. It is used for The groove D is constituted by a first groove D1 and a second groove D2. The first groove portion D1 is opposed to the front and back main surfaces of the first crystal vibrating portion 123a one by one on each of the front and back main surfaces of the first crystal vibrating portion 123a, in parallel with the longitudinal direction of the first crystal vibrating portion 123a. It is provided to be. One end of the first groove portion D1 is provided at a boundary between the first crystal vibrating portion 123a and the base 121, and the other end of the first groove portion D1 is located on the tip side of the first crystal vibrating portion 123a. Is provided. The second groove portion D2 is provided on each of the front and back main surfaces of the second crystal vibrating portion 123b, and is parallel to the longitudinal direction of the second crystal vibrating portion 123b. Are provided so as to face each other. One end of the second groove D2 is provided at the boundary between the second crystal vibrating portion 123b and the base 121, and the other end of the second groove D2 is located on the tip side of the second crystal vibrating portion 123b. Is provided. The length of the first groove portion D1 and 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.

  The projections P are used for simultaneously forming the outer shape of the tuning-fork type crystal element 120 and the grooves D due to a difference in the etching rate depending on the crystal orientation due to the etching anisotropy of the quartz crystal when the grooves D are formed by etching. It is. The protrusion P includes a plurality of first protrusions P1 provided in the first groove D1 and a plurality of second protrusions P2 provided in the second groove D2. A plurality of projections P are provided at regular intervals so as to extend in the X′-axis direction from the lengthwise side surface on the + X-axis side in the groove portion D toward the lengthwise side surface on the −X-axis side. The protrusion dimension of the protrusion P changes depending on the width of the groove D, and is about 0.005 to 0.015 mm when viewed in the length in the −X ′ direction.

  In each of the above embodiments, the protrusions P are provided at equal intervals in each groove D. However, depending on the size of the tuning-fork type crystal element 120, the distance between the protrusions P may be different. ing. By making the intervals between the projections P different in this way, the projections P provided in the grooves D formed on the front and back of the crystal vibrating portion 123 are positioned such that the projections P do not overlap when viewed through a plane. Can be arranged. Therefore, it is possible to reduce penetration of the groove D when the groove D is formed by etching.

  Further, by providing the protrusion P, when the first groove D1 and the second groove D2 are formed by etching, the etching rate of the tuning fork type crystal element 120 depends on the etching rate depending on the crystal orientation due to the etching anisotropy of the crystal. The outer shape and the groove D can be simultaneously formed by etching. Therefore, the productivity of the tuning fork type crystal element 120 can be improved.

(Second modification)
Hereinafter, a tuning fork type crystal element 120 according to a 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 is different from the tuning fork type crystal element 120 in that, as shown in FIG.

  The notch 129 is formed such that the width of the notch 129 becomes narrower as approaching the outer periphery when the surface on which the excitation electrodes 125 and 126 are formed is viewed in a plan view. In other words, the distance parallel to the length direction of the opening of the notch 129 increases toward the center of the crystal base 121. In this manner, the state of vibration between the crystal vibrating portion 123 and the crystal base 121 can be rapidly attenuated, and the vibration leakage from the portion fixed from the crystal vibrating portion 123 with the conductive adhesive 140 can be reduced. Can be further reduced, and the inhibition of vibration from the portion fixed by the conductive adhesive 140 to the crystal vibrating portion 123 can be further reduced.

  Further, by forming notch portion 129 in an arc shape, stress transmitted from crystal holding portion 122 to notch portion 129 when crystal holding portion 122 is fixed with conductive adhesive 140 is dispersed. Since it is distributed along the edge on the arc to be formed, the chipping of the crystal base 121 from the notch 129 can be suppressed.

(Third modification)
Hereinafter, the tuning fork type crystal element 120 according to the third modification of the first embodiment will be described. Note that, of the tuning fork-type crystal element in the third 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. The tuning fork type crystal element 120 according to the third modification of the first embodiment is different from the tuning fork type crystal element 120 in that, as shown in FIG. I have.

  Further, the groove D is configured by a first groove D1, a second groove D2, a third groove D3, and a fourth groove D4. The first groove portion D1 and the second groove portion D2 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 of the first crystal vibrating portion 123a. The two main surfaces are provided so as to face each other. One end of the first groove D1 and the second groove D2 is provided at a boundary between the first crystal vibrating portion 123a and the base 121, and the other end of the first groove D1 and the second groove D2 is , Are provided so as to be located on the tip side of the first crystal vibrating portion 123a. The third groove portion D3 and the fourth groove portion D4 are respectively provided on 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. Are provided so as to face each other on both front and back main surfaces. One end of the third groove D3 and the fourth groove D4 is provided at a boundary between the second crystal vibrating portion 123b and the base 121, and the other end of the third groove D3 and the fourth groove D4 is , Are provided on the tip side of the second crystal vibrating portion 123b. Further, by providing a plurality of grooves D, by applying a potential to the excitation electrodes 125 and 126 provided in the grooves D, it is possible to increase the oscillation frequency more than in the case where only one groove D is provided. This makes it easy to adjust the oscillation frequency using the frequency adjustment electrode 128.

(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 formed 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 ceramics or glass-ceramics. 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. 6, 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.

  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. The protrusion 115 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 at a position where the second electrode pad 111b is close. 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.

  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 length of the side of the convex portion 115 that is parallel to one side of the substrate 110a is 0.20 to 0.35 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.

  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 ceramics, 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 of the conductive adhesive 140 is distributed to be isotropic and concentric. A notch is formed between the crystal holding portion 122 on which the extraction electrodes 127a and 127b, which are portions fixed by the conductive adhesive 140, are formed, and the crystal vibrating portion 123 on which the excitation electrodes 125 and 126 are formed. Since the portion 129 is provided, the stress generated by the thermal expansion of the conductive adhesive 140 does not spread concentrically, but is provided in the space and the crystal base 121 between the crystal support portion 124 and the crystal vibrating portion 123. The cutout 129 is cut off. Even if the stress of the conductive adhesive 140 propagates, the stress propagates from the crystal supporting portion 124 along the edge of the crystal base 121. 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. Further, since the notch 129 is provided on the crystal base 121 on which the crystal support 124 is not provided, the notch 129 is held by the crystal holder 122 on the short side of the tuning fork type crystal element 120. In this case, it is possible to reduce the adhesion of a conductive adhesive 140 described later to the crystal vibrating portion 123. In addition, the notch 129 is formed in the direction in which the crystal support 124 is not provided (−X axis), as compared with the direction in which the crystal support 124 is provided (+ X axis). Since the residue generated at 129 becomes large, it is possible to provide a structure having improved strength against external impact.

  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 extraction electrodes 127a and 127b where the stress of the conductive adhesive 140 is fixed by the conductive adhesive 140 are formed. The space provided between the crystal holding section 122 and the crystal vibrating section 123 on which the excitation electrodes 125 and 126 are formed, and the notch 129 provided in the crystal base section 121 allow the conductive adhesive 140 to be formed. The propagation of stress will be interrupted. Even if the stress of the conductive adhesive 140 propagates, the stress propagates along the crystal supporting portion 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, since the crystal base 121 is in contact with the protrusion 115, the crystal vibrating portion 123 of the tuning-fork type crystal element 120 can be prevented from contacting the substrate 110a. 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.

  Further, in the crystal device 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.

  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 plan. 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.

(Third embodiment)
In the crystal device of the third embodiment, as shown in FIG. 10, the tuning-fork type crystal element 120 electrically connects the extraction electrode 127 provided on the crystal support portion 124 and the electrode pad 111 formed on the package 110. The second embodiment differs from the second embodiment in that the second embodiment is fixed via an adhesive 140. Note that, of the package and the tuning fork-type crystal element constituting the crystal device of the third embodiment, the same portions as those of the above-described tuning fork-type crystal element are denoted by the same reference numerals as shown in FIG. For the same parts, for example, the same reference numerals shown in FIG.

  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 of the conductive adhesive 140 is distributed to be isotropic and concentric. As described above, a space is provided between the crystal supporting portion 124 where the extraction electrodes 127a and 127b, which are the portions fixed by the conductive adhesive 140, are formed, and the crystal vibrating portion 123 where the excitation electrodes 125 and 126 are formed. As a result, the propagation of the stress generated by the thermal expansion of the conductive adhesive 140 is blocked by the space between the crystal supporting portion 124 and the crystal vibrating portion 123 without spreading concentrically. Further, even if the stress of the conductive adhesive 140 propagates, the stress propagates from the crystal supporting portion 124 along the edge of the crystal base 122. 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. In addition, when heat is applied to the crystal device, the substrate 110a is caused by the warpage of the substrate 110a due to heat from a portion where the crystal holding portion 122 on the side where the crystal support portion 124 is not formed and the electrode pad 111a are in contact. Even if the stress propagates from the electrode pad 111a to the crystal holding portion 122, the cut-off portion 129 provided in the crystal base 121 can increase the distance until the stress propagates to the excitation electrodes 125 and 126. Can be sufficiently alleviated before the stress from the transmission to the excitation electrodes 125 and 126. Therefore, the influence of the stress from the substrate 110a on the excitation electrodes 125 and 126 can be reduced.

  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 ... Protrusion 117 ... Sealing conductor pattern 120: tuning fork type crystal element 121: crystal base 122: crystal holding part 123: crystal vibrating part 124: crystal supporting part 125, 126 ... excitation electrode 127 ··· Lead electrode 128 ··· Metal film for frequency adjustment 129 ··· Notch 130 ··· Lid 131 ··· Joining member 140 ··· Conductive adhesive K · Concave D · Groove P ・ ・ ・ Protrusion

Claims (6)

An XY′Z ′ rectangular coordinate system in the crystal axis, a substantially rectangular crystal base having a thickness in a direction along the Z ′ axis;
A crystal vibrating portion provided to extend in the + Y′-axis direction from a side surface of the crystal base;
A substantially rectangular crystal holding portion provided so as to extend in the + X-axis direction and the −X-axis direction from a side surface at a position facing the side surface of the crystal base portion;
One crystal supporting portion provided only on the side surface of the crystal holding portion on the + X-axis direction side so as to extend in the + Y′-axis direction which is the same direction as the crystal vibrating portion;
When viewed in a plan view, the crystal base located between the crystal holding part and the crystal vibrating part and opposed to one side on the + X-axis direction side of the crystal base located in the position close to the crystal support part. -A notch provided only on one side in the X-axis direction side,
Excitation electrodes provided on the upper and lower surfaces of the quartz vibrating portion,
A tuning fork type crystal element comprising: a lead electrode provided from the crystal vibrating portion to the crystal base portion and the crystal support portion and electrically connected to the excitation electrode. The tuning fork type crystal element according to claim 1,
Comprising a groove provided in the quartz vibrating part,
A tuning fork type crystal element in which the excitation electrode is provided in the groove. The tuning fork type crystal element according to claim 2,
A tuning fork-type crystal element comprising a projection provided in the groove. The tuning fork type crystal element according to claim 1, wherein:
A tuning fork-type crystal element formed such that, when the surface on which the excitation electrode is formed is viewed in a plan view, the width of the notch becomes narrower as approaching the outer periphery . A tuning fork type crystal element according to claim 1,
A package comprising a substrate and a frame, and having an electrode pad provided on the substrate;
A lid for hermetically sealing the tuning-fork type crystal element. The crystal device according to claim 5, wherein
A crystal device comprising a projection on an upper surface of the substrate, the projection having a thickness in a vertical direction larger than a thickness in a vertical direction of the electrode pad.

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