JP6390206B2 - Piezoelectric oscillator - Google Patents

Description

  The present invention relates to a piezoelectric oscillator used in various electronic devices.

  A piezoelectric oscillator in which an integrated circuit element (hereinafter referred to as an IC) in which an oscillation circuit, a temperature compensation circuit, a temperature sensor, and the like are integrated, and a piezoelectric vibrating piece are housed in one package and these elements are hermetically sealed. It is used in various fields such as various communication devices.

  As an example of the piezoelectric oscillator, a crystal oscillator using a crystal vibrating piece as a piezoelectric vibrating piece is given. As an example of the configuration of a crystal oscillator, after mounting an IC on the inner bottom surface of a recess provided in a package (container), one end side of a crystal vibrating piece is joined to the upper surface of a stepped portion protruding upward from the inner bottom surface of the recess. Accordingly, there is a so-called “two-story structure” in which a crystal vibrating piece is located above an IC. A crystal oscillator having such a configuration is disclosed in Patent Document 1, for example.

JP 2002-118423

  However, the temperature compensation type crystal oscillator having the above-mentioned “two-story structure” has the following problems in performing temperature compensation of the frequency temperature characteristic of the crystal resonator element with high accuracy.

  In order to perform temperature compensation in a temperature-compensated crystal oscillator, when reading / writing an EEPROM (Electrically Erasable Programmable Read-Only Memory) mounted on an IC, a voltage higher than normal may be applied. At this time, the IC generates heat, and the heat is transmitted to the quartz crystal vibrating piece, so that the frequency may change more than in the normal oscillation state. The frequency adjustment at each temperature is performed by adjusting the load capacity by changing the ROM value. However, as shown in FIG. 7, the frequency changes greatly every time the ROM value is changed, and a stable state is obtained. There is a problem that an accurate frequency cannot be measured. FIG. 7 is a diagram in which the vertical axis represents deviation in the oscillation frequency and the horizontal axis represents time (seconds), and it can be seen that the frequency changes when accessing the ROM.

  For example, in a crystal oscillator using a tuning-fork type crystal vibrating piece as shown in Patent Document 1, it is difficult to adjust the frequency stably for the following reason. In Patent Document 1, the frequency of the crystal vibrating piece is adjusted by fixing the IC to the bottom surface of the cavity of the container and then cantilevering one end side of the crystal vibrating piece on the upper surface of the third layer of the container using a conductive adhesive. It is joined. At this time, in a plan view, the tip portions of both vibrating arms of the quartz crystal vibrating piece protrude from the upper surface of the IC. A weight portion is formed at each tip portion of both vibrating arms of the crystal vibrating piece, and the weight portion is trimmed by irradiating the weight portion with the energy beam, and the frequency is adjusted. . Here, if there is an IC mounting electrode pattern exposed on the bottom surface of the container in the area irradiated with the energy beam, the trimmed IC mounting electrode pattern metal dust scatters and crystal vibration occurs. There is a risk of adhering to one or other IC mounting electrode patterns. Here, in the tuning-fork type quartz vibrating piece, the mass change of the weight portion, which is the tip portion of the vibrating arm, affects the change in the frequency. Therefore, if metal chips adhere to the tip portion, the frequency is not stabilized during the frequency adjustment. . Moreover, there is a risk that defective insulation may occur due to metal scraps scattered by trimming adhering between the electrode patterns.

  The present invention has been made in view of the above points, and provides a more accurate piezoelectric oscillator capable of performing stable frequency adjustment and suppressing frequency change of the piezoelectric vibrating piece due to heat generation of the IC. It is intended.

To achieve the above object, according to the present invention, a tuning fork type piezoelectric vibrating piece and an integrated circuit element are accommodated in a container having a concave part opened upward, and the concave part is hermetically sealed by joining a lid to the container. The tuning fork-type piezoelectric vibrating piece includes at least a base and a pair of vibrating arms extending in the same direction from one end of the base, and at each tip side of the pair of vibrating arms, A frequency adjusting unit for adjusting the frequency of the tuning fork type piezoelectric vibrating piece is provided, and an excitation electrode for bending and vibrating the tuning fork type piezoelectric vibrating piece is formed on the base side of the vibrating arm with respect to the frequency adjusting unit. A vibration part is provided, an integrated circuit element is mounted on the inner bottom surface of the recess, and a tuning fork type piezoelectric vibrating piece is joined to the upper surface of the step part protruding upward from the inner bottom surface of the recess, thereby adjusting the frequency. Part and the frequency of the vibration part And part of the area on the side closer to the integer portion, overlaps with the integrated circuit device in plan view, of the area where said vibrating portion and the integrated circuit element are overlapped in plan view, the length in the extension direction of the vibrating arm However, it is 50% or less with respect to the length of the vibrating part in the extending direction of the vibrating arm.

  According to the above invention, the tuning fork type piezoelectric vibrating piece has at least a base and a pair of vibrating arms extending in the same direction from one end of the base, and a tuning fork is provided at each tip side of the pair of vibrating arms. A frequency adjusting unit for adjusting the frequency of the piezoelectric vibrating piece is provided, and an excitation electrode for bending and vibrating the tuning fork type piezoelectric vibrating piece is formed on the base side of the vibrating arm with respect to the frequency adjusting unit. An integrated circuit element (IC) is mounted on the inner bottom surface of the recess, and a tuning fork type piezoelectric vibrating piece is joined to the upper surface of the stepped portion protruding upward from the inner bottom surface of the recess. The entire frequency adjustment unit overlaps the integrated circuit element in plan view. With such a configuration, stable frequency adjustment can be performed.

  This is because the electrode mounting electrode pattern on the inner bottom surface of the container can be prevented from being positioned in the region irradiated with the energy beam by superimposing the entire frequency adjusting unit on the IC in plan view. That is, by making the region irradiated with the energy beam other than the frequency adjustment unit only on the upper surface of the IC, it is possible to prevent the generation of metal scraps from the IC mounting electrode pattern exposed on the inner bottom surface of the container. As a result, it is possible to prevent the trimmed electrode pattern from adhering to the quartz crystal vibrating piece and to adjust the frequency stably. Also, it is possible to prevent insulation failure due to adhesion of scattered metal scraps between the electrode patterns.

  Further, according to the above invention, the entire frequency adjustment unit and a part of the vibration unit close to the frequency adjustment unit overlap with the integrated circuit element in a plan view. The frequency change of the tuning fork type piezoelectric vibrating piece due to the heat generation of the IC can be suppressed. A portion that is a vibration source of the bending vibration of the pair of vibrating arms is a region (vibrating portion) where the excitation electrode is formed. This vibration part is an area that is easily affected by frequency changes due to heat. However, in the present invention, only a part of the vibration part on the side closer to the frequency adjustment part is superimposed on the integrated circuit element in plan view. Yes. As a result, the conduction of heat from the IC serving as the heat source to the tuning fork type piezoelectric vibrating piece can be suppressed, so that the frequency change of the tuning fork type piezoelectric vibrating piece due to heat generation from the IC at the time of ROM access can be suppressed. . As a result, more accurate temperature compensation can be performed.

According to the invention, the length of the vibrating arm in the extension direction of the vibrating portion and the integrated circuit element in a plan view is 50% of the length of the vibrating portion in the extension direction of the vibrating arm. By making the following, it is possible to more effectively suppress the frequency change of the tuning fork type piezoelectric vibrating piece due to the heat generated by the IC during ROM access. If the length in the extending direction of the vibrating arm in the region where the vibrating portion and the integrated circuit element overlap in plan view exceeds 50% of the length of the vibrating portion in the extending direction of the vibrating arm, the vibrating portion and the IC However, it is difficult to obtain the effect of suppressing the conduction of heat from the IC to the tuning-fork type piezoelectric vibrating piece in a plan view. Therefore, the length in the extending direction of the vibrating arm in the region where the vibrating part and the integrated circuit element overlap in plan view is preferably 50% or less, and 27% or less with respect to the length of the vibrating part in the extending direction of the vibrating arm. Is more effective.

  As described above, according to the present invention, it is possible to provide a highly accurate piezoelectric oscillator capable of performing stable frequency adjustment and suppressing the frequency change of the piezoelectric vibrating piece due to heat generation of the IC.

Schematic top view of a crystal oscillator according to an embodiment of the present invention Schematic sectional view taken along line AA in FIG. Enlarged schematic diagram of part B in FIG. Cross-sectional schematic diagram taken along line CC in FIG. Schematic cross-sectional view along the line DD in FIG. Schematic sectional view taken along line AA in FIG. Diagram showing frequency change in a conventional crystal oscillator

  Embodiments of the present invention will be described below with reference to the drawings. In the present embodiment, as a piezoelectric oscillator, a crystal oscillator having a temperature compensation function (temperature compensated crystal oscillator) in which a tuning fork crystal resonator element and an IC are accommodated in one package will be described as an example. FIG. 1 is a schematic top view of a crystal oscillator according to an embodiment of the present invention, and shows a state in which a lid for covering the recess 9 is not joined for convenience of explanation. 2 and 6 are schematic cross-sectional views taken along the line AA in FIG. 1, and show a state in which the lid is joined to the container.

  The crystal oscillator 1 according to the present invention includes a container 2, a crystal vibrating piece 3, an integrated circuit element (hereinafter abbreviated as IC) 4, and a lid 5 (see FIG. 2). In the present embodiment, the output frequency of the crystal oscillator 1 is 32.768 kHz.

  In FIG. 1, a container 2 is a substantially rectangular parallelepiped container having a concave portion 9 opened upward, and is configured using an insulating material as a base material. Specifically, the container 2 is a laminate of four ceramic green sheets (first layer 20, second layer 21, third layer 22, fourth layer 23 in order from the lower layer side), and is integrally formed by firing. Yes. As shown in FIG. 2, a frame-shaped metal ring 6 is attached to the upper surface of the fourth layer 23 of the container 2. A sealing material 7 is formed on the upper surface of the metal ring 6 in a circumferential shape, and the container 2 is joined to the metal lid 5 via the sealing material 7 by a seam welding method. In this embodiment, the container 2 and the lid 5 are joined under vacuum. By hermetically sealing the recess 9 in this way under vacuum, the equivalent series resistance value can be reduced as compared with the case where the recess 9 is filled with a gas such as an inert gas.

  As shown in FIG. 1, the container 2 is substantially rectangular in plan view, and its outer dimensions are 3.2 mm × 2.5 mm. The recess 9 is also substantially rectangular in plan view, and a step 8 protruding upward from the inner bottom surface 210 is formed inside the recess 9. The step portion 8 is a part of the third layer 22 exposed in the recess 9 and is formed in a circumferential shape. One end side 80 (the fixed end side of the crystal vibrating piece 3) of the stepped portion 8 is formed along one short side of the concave portion 9 having a rectangular shape in plan view, and has a shape in which the central portion of the short side is rolled up. Yes. The other end side 81 (side closer to the free end of the crystal vibrating piece) of the step portion 8 is formed along the other short side of the concave portion 9 having a rectangular shape in plan view.

  On the upper surface 800 on one end side of the stepped portion 8, two vibrating piece mounting electrodes 10 a and 10 b that are conductively joined to the tuning fork type crystal vibrating piece are formed in parallel in the container short side direction. The resonator element mounting electrodes 10a and 10b are formed with different areas, and the area of the resonator element mounting electrode 10a in plan view is larger than the area of the resonator element mounting electrode 10b in plan view. And the protrusion which protruded in the container short side direction so that it might mutually adjoin from a part of mutually opposing side of vibration piece mounting electrode 10a, 10b (so that the clearance gap between two vibration piece mounting electrodes may become narrow). Portions 101a and 101b are formed. In this way, by narrowing the side close to the center of the container long side of the opposing sides of the two vibrating piece mounting electrodes 10a and 10b locally, the protruding portion and the wide region (the opposing side of the vibrating piece mounting electrode) The boundary with the region in which no protrusion is formed is substantially perpendicular. By utilizing the right-angled portion as a point for image recognition, it is possible to improve the accuracy of image recognition when the crystal vibrating piece is positioned and mounted on the container. Thereby, even if the crystal oscillator is further downsized, the crystal resonator element can be positioned and mounted on the container with high accuracy.

  The vibrating piece mounting electrodes 10a and 10b are connected to a part of a plurality of electrode pads (not shown) on the inner bottom surface 210 via an internal wiring (not shown) and vias (not shown) provided inside the container, It is electrically connected to a part of a plurality of external connection terminals (not shown) provided on the outer bottom surface 201. The plurality of external connection terminals are formed at four corners of the container outer bottom surface 201 having a rectangular shape in plan view. These four external connection terminals are an OE (Output Enable) terminal, a ground terminal, an output terminal, and a power supply terminal.

  The inner bottom surface 210 of the container 2 is formed with a plurality of electrode pads (not shown) exposed. The plurality of electrode pads respectively correspond to the plurality of functional terminals of the IC 4, and a wiring pattern having a predetermined shape is connected to the electrode pads. The plurality of electrode pads and the wiring pattern are formed on the upper surface of the second layer 21 of the container, and the third layer 22 is laminated on the second layer 21 so that one of the plurality of electrode pads and the wiring pattern is obtained. Are exposed in the recess 9. In the description of this embodiment, the electrode pad and the wiring pattern are hereinafter referred to as an electrode pattern. The electrode pattern has a structure in which tungsten, nickel plating, and gold plating are laminated in this order from the bottom surface inside the container. The electrode pattern is formed simultaneously with the resonator element mounting electrodes 10 (10a, 10b).

  The IC 4 is a rectangular bare chip IC in which an oscillation circuit, a temperature compensation circuit, an EEPROM, a temperature sensor, and the like are integrated. The IC 4 is ultrasonically bonded to the plurality of electrode pads on the plurality of electrode pads on the inner bottom surface of the container via the metal bumps B2 so that the functional terminal surface of the IC 4 faces the inner bottom surface 210 of the container. (So-called FCB bonding).

  In FIG. 1, a crystal vibrating piece 3 is a tuning-fork type crystal vibrating piece that performs flexural vibration. As shown in FIG. 3, the quartz crystal resonator element 3 includes a base 31, a pair of vibrating arms 30 and 30 extending in one direction from one end side 310 of the base 31, and a width direction of the base from the other end 311 of the base 31 ( And a projecting portion 32 projecting in a direction substantially orthogonal to the extending direction of the vibrating arm. The vibrating arm 30 further includes an arm portion 301 (301a, 301b), a tapered portion 303, and a wide portion 302 (302a, 302b). The tapered portion 303 is a portion that continuously widens in a direction away from the terminal end side of the arm portion 301. The wide portion 302 is connected to the terminal end side of the tapered portion 303, and is formed wider than the width of the arm portion 301.

  In the quartz crystal vibrating piece 3, a large number of tuning fork type quartz crystal vibrating pieces are formed collectively from one quartz wafer. Specifically, the outer shape of the quartz crystal vibrating piece is collectively formed by a wet etching method using a resist or a metal film as a mask by using a photolithography technique. The maximum length dimension of the quartz crystal vibrating piece 3 is a dimension from the distal end portion of the wide portion 302 to the other end side 311 of the base portion, and is 1.2 mm in this embodiment. On the other hand, the maximum width dimension of the quartz crystal resonator element 3 is a dimension from the edge of the widest region in the width direction of the base to the dimension of the tip of the protrusion 32, and is 0.38 mm in this embodiment. ing.

  On the front and back main surfaces of the pair of arm portions 301a and 301b, a single groove G is formed in a substantially rectangular shape in plan view. The grooves G (G1 to G4) are formed so as to face each other on the front and back of the arm portion 301 as shown in FIG. By forming such a groove, the series resistance value of the crystal vibrating piece can be reduced. In the present embodiment, the groove G (G1 to G4) having a substantially rectangular shape in plan view has a length that does not reach the one end side 310 of the base and a length that does not reach the connection point with the tapered portion 303. It is formed on the front and back main surfaces.

  Although not shown in FIGS. 1 to 3, various electrodes (metal films) having predetermined shapes are formed on the base 31, the pair of vibrating arms 30 and 30, and the protrusion 32 using a vacuum deposition method and a photolithography technique. A pattern is formed. This will be specifically described with reference to FIGS. Among the various electrodes, the electrodes formed on the outer peripheral surfaces of the pair of arm portions 301a and 301b are excitation electrodes for driving the quartz crystal vibrating piece (see FIG. 4). That is, a pair of main surface electrodes E1, E2 (E5, E6) provided on two opposing main surfaces of the arm portion 301a (302b) and two opposing side surfaces of the arm portion 301a (302b). A pair of side surface electrodes E7, E8 (E3, E4) is an excitation electrode. The first excitation electrode includes main surface electrodes E1 and E2 of the arm portion 301a and side surface electrodes E3 and E4 of the arm portion 301b, which are connected to each other. Similarly, the second excitation electrode includes main surface electrodes E5 and E6 of the arm portion 301b and side surface electrodes E7 and E8 of the arm portion 301a, which are connected to each other. The first excitation electrode and the second excitation electrode have different polarities, and by applying an electric field to the electrode having such a configuration, the pair of vibrating arms flexurally vibrate. The main surface electrodes E1 and E2 (E5 and E6) are formed to extend to the inner peripheral surfaces of the grooves G1 to G4.

  Each of the first excitation electrode and the second excitation electrode has a configuration in which chromium is used as a base layer and an upper gold layer is stacked, and is formed by a photolithography technique. The first excitation electrode and the second excitation electrode are led out to the front and back surfaces of the base 31 and the protrusion 32 through a side surface of the base and through holes (not shown) provided in the base.

  As shown in FIG. 5, on the entire circumference of the outer peripheral surfaces (two main surfaces facing each other on the front and back sides and two side surfaces facing the inner and outer surfaces) constituting the wide portions 302a and 302b, A metal film 312 is formed to commonly connect the side electrodes E3 and E4 and the side electrodes E7 and E8 of 301b (only the wide portion 302a is displayed in FIG. 5 and the display of the wide portion 302b is omitted). That is, no electrode having a different polarity is formed on the wide portion 302. In the present embodiment, the metal film 312 has a film structure in which a base layer made of chromium and a gold layer are stacked thereon.

  Of the metal film 312 formed on the outer periphery of the wide portion 302, a weight (metal film) W made of frequency adjusting silver or the like is formed by vapor deposition in regions corresponding to the front and back main surfaces of the wide portion. (FIG. 5). Fine tuning of the frequency of the tuning-fork type quartz vibrating piece is performed by reducing the mass of the weight by irradiation with an ion beam or the like. In FIG. 3, for convenience of explanation, only the excitation electrodes (main surface electrodes E1, E5) formed in the grooves G1, G3 and the frequency adjusting weight W are displayed.

  In the tuning-fork type crystal vibrating piece, the vibrating arm is flexibly vibrated by applying an electric field to the first excitation electrode vibration and the second excitation electrode vibration. Therefore, the part which becomes the vibration source of the bending vibration in the tuning-fork type crystal vibrating piece is an area where the excitation electrodes E1 to E8 are formed in the pair of vibrating arms. Hereinafter, the region serving as a vibration source of flexural vibration is referred to as a vibration part. In the present embodiment, the vibration part has a substantially rectangular shape with the extending direction of the vibrating arm as a longitudinal direction in a plan view, and the range in the longitudinal direction is denoted by a symbol L in FIG.

  A connection electrode (not shown) that is conductively joined to the outside is formed on each of the other end 311 of the base portion 31 of the crystal vibrating piece 3 and the protruding portion 32. These connection electrodes have a structure in which gold is laminated on the upper layer of the chromium underlayer, and are formed simultaneously with the formation of the excitation electrodes E1 to E8 of the vibrating arm. On the connection electrodes, metal bumps B1 (B1a, B1b) are formed by electrolytic plating, and are FCB-bonded to the resonator element mounting electrodes 10a, 10b of the stepped portion 8 of the container 2 (FIG. 2 to FIG. 2). 3).

  As described above, the IC 4 is mounted on the inner bottom surface 210 of the recess 9. The connection electrodes of the crystal resonator element 3 are conductively bonded to the resonator element mounting electrodes 10a and 10b provided on the upper surface 800 of the step portion 8 via bumps. Thereby, a part of a pair of vibrating arms 30 and 30 is located above IC4. Specifically, as shown in FIG. 3, the relative positional relationship in plan view after the quartz crystal resonator element 3 and the IC 4 are mounted on the container 2 depends on the entire frequency adjustment unit 302 and the frequency adjustment unit 302 of the vibration unit. A part of the region on the near side overlaps with the IC 4.

  According to the above configuration, stable frequency adjustment can be performed. This is because the entire frequency adjustment unit 302 is superimposed on the IC in plan view, so that the electrode mounting electrode pattern on the inner bottom surface 210 of the container is not located in the region irradiated with the energy beam. Because. In other words, by making the region irradiated with the energy beam other than the frequency adjustment unit 302 only on the upper surface of the IC 4, it is possible to prevent the generation of metal scraps from the IC mounting electrode pattern exposed on the inner bottom surface 210 of the container. it can. Thereby, it is possible to prevent the trimmed electrode pattern from adhering to the quartz crystal vibrating piece 3 and to adjust the frequency stably. Also, it is possible to prevent insulation failure due to adhesion of scattered metal scraps between the electrode patterns.

  Further, according to the above configuration, the entire frequency adjustment unit 302 and a part of the vibration unit on the side close to the frequency adjustment unit 302 overlap with the IC 4 in plan view. It is possible to suppress the frequency change of the crystal vibrating piece 3 due to the heat generation of the IC. The “vibrating part” that is the vibration source of the bending vibration of the pair of vibrating arms 301a and 301b is an area that is easily affected by the frequency change due to heat. In the present invention, the vibrating part is on the side closer to the frequency adjusting part. Only a part of the area overlaps with the IC in plan view. Thereby, conduction of heat from the IC 4 serving as a heat source to the crystal vibrating piece 3 can be suppressed, and a change in the frequency of the crystal vibrating piece 3 due to heat generated from the IC at the time of ROM access can be suppressed. As a result, more accurate temperature compensation can be performed.

  In this embodiment, the dimension R in the length direction of the region where the vibration part and the IC overlap in plan view is about 0.193 mm, and the length L in the extension direction of the vibration arm of the vibration part is about 0.1 mm. It is 71 mm. The length R in which the vibration part overlaps with the IC in plan view is preferably about 27% or less in the extension direction of the pair of vibration arms 301a and 301b with respect to the length L of the vibration part in the extension direction of the vibration arm. .

  In the present embodiment, the vertical gap (symbol d in FIG. 6) from the lower surface of the vibrating portion of the crystal vibrating piece 3 to the upper surface 400 of the IC 4 is 0.05 mm or more (0.12 mm or less). When the gap “d” is 0.05 mm or less, the vibrating portion of the crystal vibrating piece and the IC are too close to each other, and heat from the IC during ROM access is easily conducted to the crystal vibrating piece. Thereby, the frequency of the crystal vibrating piece tends to be unstable. In addition, when the gap “d” is 0.05 mm or less, there is a risk that the crystal resonator piece and the IC come into contact with each other when the crystal oscillator receives an external impact or the like due to a bonding variation between the crystal resonator element and the electrode mounted on the resonator element. Will increase. Therefore, it is desirable to secure the gap “d” of 0.05 mm or more.

  In this embodiment, the dimension R in the length direction of the region where the vibration part overlaps the IC in plan view is the length L of the vibration part in the extension direction of the vibration arm in the extension direction of the pair of vibration arms 301a and 301b. On the other hand, it is about 27% or less, but the ratio may be 27% or more. For example, when the ratio is 27% or more and 50% or less, the region where the vibration part and the IC overlap in plan view is larger than when the ratio is 27% or less. By setting the gap as large as possible, it is possible to suppress a change in the frequency of the crystal resonator element due to heat generated from the IC during ROM access.

  In the present embodiment, a four-layer configuration is taken as an example of a container that is a laminate of ceramic sheets, but the container may be configured with four layers or less, or four layers or more. In this embodiment, the electromechanical joining between the crystal vibrating piece and the vibrating piece mounting electrode of the container is performed through the conductive bump. However, a conductive adhesive is used instead of the conductive bump. May be. In the present embodiment, the crystal vibrating piece 3 is a tuning fork type crystal vibrating piece having a base, a pair of vibrating arms, and a protruding portion. However, the crystal vibrating piece 3 has only a base and a pair of vibrating arms and has a protruding portion. It may be a shape that does not. Further, in the present embodiment, the protruding portion has a shape protruding in only one direction from the base portion, but may have a shape protruding in a direction away from the other end side of the base portion. Alternatively, it may be a shape that protrudes in a direction away from the other end side of the base, and then bent so as to extend in parallel with the extending direction of the vibrating arm.

  The present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-described embodiment is merely an example in all respects and should not be interpreted in a limited manner. The scope of the present invention is indicated by the claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the equivalent scope of the claims are within the scope of the present invention.

  It can be applied to mass production of piezoelectric oscillators.

DESCRIPTION OF SYMBOLS 1 Crystal oscillator 2 Container 3 Crystal vibrating piece 4 Integrated circuit element 5 Lid 6 Metal ring 7 Sealing material 8 Step part 9 Recessed part 10 Vibrating piece mounting electrode 301 Arm part 302 Frequency adjustment part

Claims (1)

A piezoelectric oscillator in which a tuning fork-type piezoelectric vibrating piece and an integrated circuit element are accommodated in a container having a recess opened upward, and the recess is hermetically sealed by joining a lid to the container,
The tuning fork type piezoelectric vibrating piece has at least a base portion and a pair of vibrating arms extending in the same direction from one end side of the base portion,
Each tip side of the pair of vibrating arms is provided with a frequency adjusting unit for adjusting the frequency of the tuning fork type piezoelectric vibrating piece,
On the base side of the vibrating arm with respect to the frequency adjusting unit, a vibrating unit in which an excitation electrode for bending and vibrating the tuning fork type piezoelectric vibrating piece is provided,
An integrated circuit element is mounted on the inner bottom surface of the recess, and a tuning fork type piezoelectric vibrating piece is joined to the upper surface of the stepped portion protruding upward from the inner bottom surface of the recess.
The entire frequency adjustment unit and a part of the vibration unit on the side close to the frequency adjustment unit overlap with the integrated circuit element in a plan view, and the vibration unit and the integrated circuit element overlap in a plan view. The piezoelectric oscillator according to claim 1, wherein a length of the vibrating arm in the extending direction of the vibrating portion is 50% or less with respect to a length of the vibrating portion in the extending direction of the vibrating arm.

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