Piezoelectric vibrator container and piezoelectric vibrator

Abstract

The present invention relates to a piezoelectric vibrator container and a piezoelectric vibrator, which avoid breakage of internal wiring based on ion milling. A piezoelectric vibrator (1) is housed in a piezoelectric vibrator container (2), and a support arm portion (9) of a side arm type piezoelectric vibration piece (6) is fitted to a mounting portion (14) formed by a metal protrusion, and is sealed by a sealing plate (4) after frequency adjustment based on ion milling. In an internal electrode (32) formed on an inner surface (10f) of a bottom plate (10), at least a portion of the internal electrode (32) (a side away from an opening window (81)) other than the periphery of the opening window (81) ion milled is formed between the bottom plate (10) and an upper frame (11), so that a portion of the internal electrode (32) is covered by the upper frame (11). Thus, even if a portion of the internal electrode (32) exposed is assumed to be damaged due to ion milling, since the covered portion remains, breakage of the internal electrode (32) can be reliably avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to a piezoelectric vibrator container and a piezoelectric vibrator, and more particularly to a piezoelectric vibrator container and a piezoelectric vibrator in which a piezoelectric vibration piece is provided inside. BACKGROUND

[0002] In various electronic devices such as a cellular phone, a portable information terminal device, and the like, a piezoelectric vibrator using quartz or the like is widely used as a device for a timing source, a control signal, a reference signal, and the like. As such a piezoelectric vibrator, as shown in Patent Document 1, a structure in which a piezoelectric vibration piece is hermetically sealed in a cavity formed by a case and a lid is known. The piezoelectric vibration piece has a base portion of a prescribed length formed of a piezoelectric material, and a pair of vibration arm portions extending side by side from the base portion, and has a pair of support arm portions for fixation extending side by side from both side end sides of the base portion outside the vibration arm portions. In a piezoelectric vibrator in which such a piezoelectric vibration piece is housed, for example, as shown in Patent Document 1, a frequency adjustment is performed on the piezoelectric vibration piece housed in the case by removing a metal film at the front end of the vibration arm portion by an ion milling method. That is, a mask in which an opening window corresponding to a removal target region of the metal film is provided is placed on the piezoelectric vibration piece, and ions are irradiated from the opening window, whereby the metal film at the front end of the vibration arm portion is removed.

[0003] Further, an internal electrode for connecting an external electrode to an excitation electrode of two systems formed in the piezoelectric vibration piece is formed on the inner side bottom surface of the piezoelectric vibrator case (container). Moreover, with recent miniaturization, the region in which the internal electrode is provided becomes smaller to the extent that the volume of the case becomes smaller, and there is a tendency for the front end of the vibration arm portion and the internal electrode to come close to each other. Furthermore, in the case of a piezoelectric vibration piece fixed by the support arm portions, the lateral width becomes larger compared to a so-called cantilever type piezoelectric vibration piece, and thus it is necessary to form the internal electrode in the case in the vicinity of the vibration arm portion.

[0004] Due to such miniaturization of the case, the shape of the piezoelectric vibration piece, and the like, in the case where the internal electrode is formed in the vicinity of the vibration arm portion, if a frequency adjustment based on ion milling is performed, the internal electrode can be broken. That is, in ion milling, ions are irradiated from the opening window formed in the mask at the front end of the vibration arm portion, but the irradiated ions diffuse in the case, and the ions are irradiated not only to the metal film at the front end of the vibration arm portion but also to the internal electrode, and as a result, the internal electrode is sometimes broken.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT DOCUMENTS

[0007] Patent Document 1: Japanese Patent Application Publication No. 2006-165968 SUMMARY

[0008] Problems to be Solved by the Invention

[0009] The present invention aims to avoid breakage of internal wiring based on ion milling.

[0010] Means for Solving the Problems

[0011] (1) In the invention described in Technical Solution 1, a piezoelectric vibrator container is provided, characterized by comprising: a bottom plate; an annular upper frame that forms a concave portion that accommodates a piezoelectric vibration piece together with the bottom plate, disposed on an upper portion of the bottom plate; a mounting portion formed on an inner surface of the bottom plate on a side of the upper frame disposed on the bottom plate, for mounting the piezoelectric vibration piece; a pair of internal electrodes formed on the inner surface of the bottom plate, electrically connected via the mounting portion, to a pair of excitation electrodes formed on the piezoelectric vibration piece; and a portion of the length direction of the piezoelectric vibration piece covered by the upper frame among the internal electrodes.

[0012] (2) In the invention described in Technical Solution 2, the piezoelectric vibrator container described in Technical Solution 1 is characterized in that a piezoelectric vibration piece provided with a pair of mounting support arm portions on both outer sides of a vibration arm portion is taken as a mounting object, and the mounting portion is formed in a pair at positions corresponding to the support arm portions.

[0013] (3) In the invention described in Technical Solution 3, the piezoelectric vibrator container described in Technical Solution 2 is characterized in that a portion of the length direction of the internal electrodes is covered by the upper frame, and the remaining portion of the length direction is exposed within the concave portion.

[0014] (4) In the invention described in Technical Solution 4, the piezoelectric vibrator container described in Technical Solution 1, Technical Solution 2, or Technical Solution 3 is characterized in that a portion of the length direction of the internal electrodes disposed extending from the mounting portion to the side of the vibration arm portion of the piezoelectric vibration piece is covered by the upper frame among the internal electrodes.

[0015] (5) In the invention described in Technical Solution 5, the piezoelectric vibrator container described in any one of Technical Solution 1 to Technical Solution 4 is characterized in that the width of the internal electrodes covered by the upper frame is 1 / 3 or less of the width of the upper frame.

[0016] (6) In the invention described in Technical Solution 6, the piezoelectric vibrator container described in any one of Technical Solution 1 to Technical Solution 4 is characterized in that the width of the internal electrodes covered by the upper frame is 1 / 4 or less of the width of the upper frame.

[0017] (7) In the invention described in the technical solution 7, the piezoelectric vibrator is characterized by comprising the piezoelectric vibrator container described in any one of the technical solutions 1 to 6, the piezoelectric vibration piece mounted to the mounting portion, and the sealing plate connected to the surface of the open side of the recessed portion and sealingly housing the mounted piezoelectric vibration piece in the recessed portion.

[0018] Effects of the Invention

[0019] According to the present invention, in a pair of internal electrodes formed on the inner surface of the bottom plate, a part of the length direction of the piezoelectric vibration piece is covered by the upper frame, so that the breakage of internal wiring caused by frequency adjustment based on ion milling can be avoided. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is an exploded perspective view of a piezoelectric vibrator in which the piezoelectric vibrator container is provided with a piezoelectric vibration piece.

[0021] Figure 2 is an explanatory view showing the wiring state of the internal electrodes on the inner surface of the bottom plate of the piezoelectric vibrator container.

[0022] Figure 3 is an explanatory view showing the wiring state of the external electrodes on the back surface of the bottom plate of the piezoelectric vibrator container.

[0023] Figure 4 is an explanatory view showing the state of the back surface of the lower frame of the piezoelectric vibrator container.

[0024] Figure 5 is an explanatory view showing the state of ion milling of the piezoelectric vibration piece.

[0025] Figure 6 is an explanatory view of the piezoelectric vibrator in the second embodiment. DETAILED DESCRIPTION

[0026] Hereinafter, a suitable embodiment of the piezoelectric vibration piece and the piezoelectric vibrator of the present invention will be described in detail with reference to the drawings. Figures 1 to 6

[0027] (1) Summary of the Embodiment

[0028] ​In this embodiment, the piezoelectric vibrator 1 is housed within the piezoelectric vibrator container 2. The support arms 9a and 9b of the so-called side-arm type piezoelectric vibrator 6 are fitted to mounting portions 14a and 14b formed by metal protrusions. After frequency adjustment based on ion milling, the vibrator is sealed by a sealing plate 4. Internal electrodes 31 and 32 serving as wiring are formed on the inner surface 10f of the base plate 10 constituting the piezoelectric vibrator container 2. In this embodiment, among the internal electrodes 32 formed on the inner surface 10f of the base plate, at least a portion of the periphery of the ion-milled opening window 81 (the side away from the opening window 81) is formed between the base plate 10 and the upper frame 11.

[0029] That is, a portion of the internal electrode 32 is covered by the upper frame 11. Therefore, even if the exposed portion of the internal electrode 32 not covered by the upper frame 11 is damaged due to ion milling, the covered portion remains, thus reliably preventing wire breakage of the internal electrode 32. Furthermore, even for a piezoelectric vibrator 1 equipped with a piezoelectric vibrator 6, it can be manufactured without reducing yield or performance. Therefore, further miniaturization of the piezoelectric vibrator 1 becomes possible.

[0030] Furthermore, although the entire periphery of the internal electrode 32 around the opening window 12 can be covered by the upper frame 11, it is preferable to cover only a portion in order to maintain the connection strength between the base plate 10 and the upper frame 11. The area of ​​the internal electrode 32 covered by the upper frame 11 is less than 1 / 3 of the width of the upper frame 11, preferably less than 1 / 4. In addition, to enable confirmation of the arrangement state of the internal electrode 32 based on visual observation, image recognition, etc., it is also preferable that the area covered by the upper frame 11 is only a portion.

[0031] (2) Details of the implementation method

[0032] [First Implementation Method]

[0033] Figure 1 This is an exploded perspective view of the piezoelectric vibrator 1 according to the first embodiment, in which a piezoelectric vibrating plate 6 is disposed in the piezoelectric vibrator container 2. Figure 1 As shown, the piezoelectric vibrator 1 of this embodiment is a surface-mount type vibrator with a ceramic housing. It includes a piezoelectric vibrator container 2 with an internal accommodating space, a sealing plate 4 for the airtight piezoelectric vibrator container 2, and a piezoelectric vibrating plate 6 housed within the piezoelectric vibrator container 2. As an example of top-view dimensions, the piezoelectric vibrator 1 is formed with a length of approximately 1.6 mm and a width of approximately 1.2 mm. Furthermore, the piezoelectric vibrator 1 of this embodiment has a bilaterally symmetrical structure. Therefore, like the vibrating arm 7a and vibrating arm 7b, the two symmetrically arranged parts are represented by the same numbers, and to distinguish the two parts, a distinguishing symbol 'a' is added to one and a distinguishing symbol 'b' is added to the other. However, the distinguishing symbols are appropriately omitted in the description, but in this case, they still refer to their respective parts.

[0034] The piezoelectric vibrator 6 is a so-called tuning fork-shaped vibrator made of piezoelectric materials such as quartz, lithium tantalate, and lithium niobate, which vibrates when a predetermined voltage is applied. In this embodiment, a piezoelectric vibrator made of quartz as the piezoelectric material will be used as an example. The piezoelectric vibrator 6 is a so-called side-arm type quartz vibrator, which has a pair of vibrating arms 7a and 7b extending parallel to the base 8, and a pair of supporting arms 9a and 9b extending from the base 8 in the same direction outside the vibrating arms 7. The piezoelectric vibrator 6 is held by the mounting portions 14a and 14b inside the piezoelectric vibrator container 2 by the supporting arms 9a and 9b.

[0035] A pair of vibrating arms 7a and 7b are arranged parallel to each other, vibrating with the ends on the base 8 side as fixed ends and the front ends as free ends. The pair of vibrating arms 7a and 7b have widened portions 71a and 71b on their free end sides that are wider on both sides than on the base end sides. Furthermore, grooves are formed along the length direction in the vibrating arms 7a and 7b from the ends on the base 8 side to near the widened portions 71a and 71b. Alternatively, a piezoelectric vibrator without the widened portions 71a and grooves can also be used.

[0036] In the piezoelectric vibrator 6 of this embodiment, although not shown, a counterweight metal film is formed at the front ends (widened portions 71a, 71b) of the vibrating arms 7a, 7b. This counterweight metal film is used to adjust the vibration state (frequency adjustment) so that the vibration is within a specified frequency range. Furthermore, after the piezoelectric vibrator 6 is installed (assembled) into the mounting portions 14a, 14b of the piezoelectric vibrator container 2, a portion of the counterweight metal film formed at the front ends of the vibrating arms 7a, 7b is removed by ion milling, thereby enabling the frequency to be controlled within the rated frequency range of the device. Additionally, the counterweight metal film of the piezoelectric vibrator 6 can also be partially removed, for example, by irradiating the piezoelectric vibrator container 2 before installation, thereby performing frequency adjustment. In this case, ion milling is performed as the final frequency adjustment.

[0037] The piezoelectric vibrator container 2 is formed in an approximately cuboid shape, and includes a concave portion 3 and a sealing ring 13 that seals the concave portion 3. Furthermore, the piezoelectric vibrator container 2 of this embodiment does not include a sealing plate 4 that engages with the sealing ring 13 for airtight sealing, but it can also include a sealing plate 4 to form a piezoelectric vibrator container 2. The concave portion 3 includes a flat bottom plate 10 that engages when stacked, an annular upper frame 11 engaged with the upper surface of the bottom plate 10, and an annular lower frame 12 engaged with the lower surface of the bottom plate 10.

[0038] At the four corners of the joined base plate 10, upper frame 11, and lower frame 12, a quarter-circular cutout 15, viewed from above, is formed throughout the entire thickness direction. These base plates 10, upper frames 11, and lower frames 12 are manufactured by stacking and joining three ceramic substrates, such as wafers, forming multiple through-holes penetrating two of the ceramic substrates in a row, and then simultaneously cutting the two ceramic substrates into a grid pattern based on each through-hole. At this point, the through-holes are divided into four parts, thus forming the cutout 15.

[0039] In addition, the base plate 10, the upper frame 11 and the lower frame 12 are made of ceramic, but specific ceramic materials can be listed as such as HTCC (High Temperature Co-Fired Ceramic) made of alumina and LTCC (Low Temperature Co-Fired Ceramic) made of glass ceramic.

[0040] The concave portion 3 is formed by stacking the upper frame 11, the base plate 10, and the lower frame 12 in that order, starting from the top. The upper frame 11 and the lower frame 12 are bonded to the base plate 10 by sintering or the like. That is, the upper frame 11 and the lower frame 12 are integrated with the base plate 10. Furthermore, although... Figure 1 Not shown in the diagram, but as described later, internal electrodes 31 and 32 and external electrodes 23 and 24 are formed on both surfaces of the base plate 10. A portion of the internal electrodes is formed in a state where it is sandwiched between the base plate 10 and the upper frame 11. Additionally, mounting portions 14a and 14b for mounting the piezoelectric vibrating sheet 6 are formed on the inner surface 10f of the base plate 10. These mounting portions 14a and 14b are located on the internal electrodes 31a and 31b (see reference 1). Figure 2 The top is formed by metallic protrusions.

[0041] The upper frame 11 and the lower frame 12 form an internally continuous ring. The inner surface 11n of the piezoelectric vibrator 1 and the inner surface 12n of the lower frame 12 (see reference) Figure 2 All are formed into a rectangular shape with rounded corners when viewed from above. External electrodes 22 are formed in the cutout 15 of the concave portion 3 at four locations of the cutout 15 of the lower frame 12.

[0042] The sealing ring 13 is a conductive frame-shaped component that is smaller in shape than the concave portion 3, and is joined to the upper surface of the upper frame 11. Specifically, the sealing ring 13 is joined to the upper frame 11 by firing based on brazing materials such as silver solder or welding materials, or by welding of a metal bonding layer formed on the upper frame 11 (e.g., by vapor deposition, sputtering, etc., other than electrolytic plating or electroless plating).

[0043] Examples of materials that can be used for the sealing ring 13 include nickel-based alloys, specifically Kovar, Elinvar, Invar, and 42 iron-nickel alloys. In particular, the material for the sealing ring 13 is preferably chosen to have a coefficient of thermal expansion close to that of the ceramic base plate 10 and the upper frame 22. For example, a coefficient of thermal expansion of 6.8 × 10⁻⁶ is used for the base plate 10 and the upper frame 11. -6 In the case of alumina at a temperature of / ℃, a sealing ring 13 preferably uses an alumina with a thermal expansion coefficient of 5.2×10⁻⁶. -6 Kovar alloy at / ℃, coefficient of thermal expansion 4.5-6.5×10 -6 42 iron-nickel alloy at / ℃.

[0044] The sealing plate 4 is a conductive substrate superimposed on the sealing ring 13. The sealing plate 4 is welded to the sealing ring 13 by means of seam welding, laser welding, ultrasonic welding, etc., which causes the roller electrodes to move in contact, thereby achieving an airtight connection with the piezoelectric vibrator container 2. Moreover, the space defined by the sealing plate 4, the sealing ring 13, the inner side of the upper frame 11, and the inner surface 10f of the bottom plate 10 functions as an airtightly sealed cavity.

[0045] Figure 2 This is a diagram showing the side cross-section of the piezoelectric vibrator container 2 and the wiring state of the internal electrodes on the inner surface 10f of the container's bottom plate. Figure 2 (a) represents a cross section along the length of the mounting portion 14b disposed on the base plate 10. Figure 2 (b) indicates the state of the inner surface 10f of the bottom plate 10 as viewed from above through the sealing ring 13 and the upper frame 11 of the piezoelectric vibrator container 2. Figure 2 (b) The dashed box represents the inner surface 11n of the upper frame 11. For example... Figure 2 As shown in (b), through electrodes 30a, 30b, and 30c, which extend through the thickness direction, are formed at three locations among the four corners of the base plate 10. The through electrodes 30 are formed, for example, in through holes formed in the base plate 10, by filling with metal flux (conductive flux), inserting metal pins through the holes, or plating the inner circumferential surface.

[0046] Through electrodes 30a and 30b are positioned approximately diagonally on the inner side of the upper frame 11, which is shown in dashed lines. Specifically, a portion of the end face of the through electrodes 30a and 30b on the upper frame 11 side is covered by the upper frame 11. The opposite end faces of the through electrodes 30a and 30b are connected to the external electrodes 24a and 24b via connecting electrodes 25a and 25b formed on the outer surface 10r of the base plate 10 (see reference). Figure 3 ).

[0047] On the other hand, in the through electrode 30c, the end face on the side of the upper frame 11 is integrally formed at the position covered by the upper frame 11. The through electrode 30c is provided to achieve conductivity when the sealing ring 13 is connected by plating. Therefore, unlike the through electrodes 30a and 30b which are formed only in the base plate 10, the through electrode 30c is formed through the upper frame 11 in addition to the base plate 10. The end face of the through electrode 30c on the side of the base plate 10 is connected to the external electrode 23 via a connecting electrode 25c formed on the outer surface 10r of the base plate (see reference). Figure 3 The opposite end face is connected to the metallization layer (not shown) formed integrally on the upper surface of the upper frame 11.

[0048] Between the mounting portions 14a, 14b and the inner surface 10f of the base plate, the internal electrodes 31a, 31b, which are larger than the mounting portions 14a, 14b, are formed in an elongated oval shape. Furthermore, the mounting portions 14a, 14b and the internal electrodes 31a, 31b are as follows... Figure 2 As shown, it is positioned further to one side than the center in the longitudinal direction (left-right direction in the attached figure) (left side in the attached figure). Moreover, the piezoelectric vibrating plate 6 is mounted on this side in the direction where the base 8 is located.

[0049] On the side of the through electrode 30c at the four corners of the inner surface 10f of the base plate, an electrode connected to the connecting electrode 33c is formed on the inner side of the inner surface 11n of the upper frame 11. This electrode is an index mark 35 used to determine the direction (left and right direction in the figure) of the concave portion 3 by image recognition.

[0050] On the inner surface 10f of the base plate, circular connecting electrodes 33a-33c are formed at positions corresponding to the through electrodes 30a-30c. These connecting electrodes 33a-33c are also covered by the upper frame 11, specifically the portion of the outer side visible from the center of the inner surface 10f of the base plate. Furthermore, the inner electrode 31a and the connecting electrode 33a are connected by an inner electrode 32a, and the inner electrode 31b and the connecting electrode 33b are connected by an inner electrode 32b. That is, the inner electrodes 32a and 32b are as follows... Figure 2 As shown in (b), the electrodes are formed to extend outwards in the width direction (vertical direction in the attached figure) from the inner electrodes 31a and 31b, and are bent away from the center in the length direction. The front end is connected to the connecting electrodes 33a and 33b. Furthermore, a portion of the outer side of the portion of the inner electrodes 32a and 32b extending in the length direction is covered by the upper frame 11. Therefore, even if the exposed portion of the inner electrode 32 not covered by the upper frame 11 is damaged due to ion milling, the breakage of the inner electrode 32 can be reliably avoided.

[0051] Figure 3 This is an explanatory diagram showing the wiring configuration of the external electrodes on the back side 10r of the base plate of the piezoelectric resonator container 2. Furthermore, Figure 3The back side 10r of the base plate shown is a perspective view of the piezoelectric resonator container 2 viewed from above through the upper frame 11 and the base plate 10. (See diagram below.) Figure 3 As shown, external electrodes 22 (refer to) are formed on the outer surface 10r of the base plate and at the cutouts 15 at the four corners of the lower frame 12. Figure 1 External electrodes 23, which are connected to each through electrode 30a-30c (see reference), are formed at four locations. Figure 2 (b) The corresponding positions are provided with connecting electrodes 25a-25c. The connecting electrode 25c is connected to the external electrode 23.

[0052] Additionally, external electrodes 24a and 24b are formed on the outer surface 10r of the substrate. External electrode 24a is connected to the mounting portion 14a via a through electrode 30a, an internal electrode 32a, and an internal electrode 31a through a connection electrode 25a. External electrode 24b is connected to the mounting portion 14b via a through electrode 30b, an internal electrode 32b, and an internal electrode 31b through a connection electrode 25b. External electrodes 24a and 24b are electrodes used to mount an IC on the back surface 10r of the substrate.

[0053] Figure 3 The dashed box shown represents the inner surface 12n of the lower frame 12. That is, among the external electrodes 23, external electrodes 24a, 24b and connecting electrodes 25a-25c formed on the back surface 10r of the base plate 10, the area further outward than the inner surface 12n of the lower frame 12 represented by the dashed line is covered by the lower frame 12.

[0054] Figure 4 This diagram shows the state of the back side of the lower frame 12 of the piezoelectric resonator container 2. External electrodes 21 are formed at the four corners of the back side of the lower frame 12. Each of the four external electrodes 21 is connected to a connecting electrode 22 formed at the cutout 15 at the four corners of the lower frame 12 (see reference). Figure 1 Furthermore, although in Figure 4 Although not explicitly stated, when the piezoelectric resonator container 2 is viewed from below (the side of the lower frame 12), there is a [missing information - likely a feature or characteristic] inside the inner surface 12n of the lower frame 12. Figure 3 The outer electrodes 23, 24a, 24b and connecting electrodes 25a-25c within the inner surface 12n, shown by dashed lines.

[0055] The concave portion 3 of this embodiment (refer to) Figure 1 It is made of ceramics such as alumina and is formed by stacking and firing multiple flexible ceramic sheets, known as green sheets, together. The thickness and number of each sheet are appropriately selected considering the thickness of the lower frame 12, the base plate 10, and the upper frame 11.

[0056] On each sheet, the various electrodes (internal and external electrodes) described above are formed by, for example, conductor printing, and through electrodes 30a-30c are formed. Then, the lower frame 12, the base plate 10, and the upper frame 11 are stacked in sequence, and then the whole assembly is fired simultaneously. After the concave portion 3 is fired, a layer of brazing material is formed on the metallization layer formed on the upper surface of the upper frame 11, and the sealing ring 13 is joined thereto by seam welding, thereby forming the piezoelectric oscillator container 2.

[0057] Next, regarding in such Figures 2 to 4 The piezoelectric vibrator container 2, constructed in this manner, includes the installation of the piezoelectric vibrator 6 and the manufacture of the piezoelectric vibrator 1 based on ion milling frequency adjustment. In the piezoelectric vibrator 6, electrodes are connected from two excitation electrodes (first and second excitation electrodes) for pre-excitation to the vibrating arms 7a and 7b. Furthermore, a counterweight metal film for frequency adjustment is formed at the widened portions 71a and 71b at the front ends of the vibrating arms 7a and 7b. Before installation, the frequency of the installed piezoelectric vibrator 6 is adjusted to a predetermined level by removing the counterweight metal film.

[0058] Figure 5 This is an explanatory diagram showing the state of ion milling of the piezoelectric vibrator 6. First, the piezoelectric vibrator 6 is placed on the mounting portions 14a and 14b in the piezoelectric oscillator container 2. That is, after applying a conductive adhesive to the mounting portions 14a and 14b, the support arms 9a and 9b of the piezoelectric vibrator 6 are placed on the conductive adhesive. Then, the conductive adhesive is applied by baking the piezoelectric oscillator container 2 on which the piezoelectric vibrator 6 is placed, thereby mounting the piezoelectric vibrator 6 onto the piezoelectric oscillator container 2.

[0059] The piezoelectric vibrator container 2, on which the piezoelectric vibrator 6 is mounted, is placed in a clamp within a box (not shown). Then, as... Figure 5 As shown, a mask 80, in which openings 81 (frames surrounded by a dotted line) are formed around the periphery of the widened portions 71a and 71b of the piezoelectric vibrator 6 to be trimmed, is set on the piezoelectric vibrator container 2 (mask setting process). Thus, in the piezoelectric vibrator 6, the base 8, the support arm 9, the vibrating arm 7 (excluding the widened portion 71), and the end portion 8 of the widened portion 71 are covered by the mask 80, while the front end portion 71 is exposed. Furthermore, the base 8 side of the vibrating arm 7 is covered by the mask 80 to prevent the removal of the first excitation electrode and the second excitation electrode formed on the vibrating arm 7 by ion milling.

[0060] Next, the piezoelectric oscillator container 2 set inside the chamber is subjected to ion milling. Specifically, the chamber is depressurized and a process gas such as argon is introduced. If an accelerating voltage is applied under this state, the ionized process gas collides with the counterweight metal of the vibrating arm 7 through the opening window 81 of the mask 80. As a result, the counterweight metal film of the vibrating arm 7 is bounced off from the surface, the mass of the vibrating arm 7 changes, and thus the frequency of the vibrating arm changes. In the piezoelectric oscillator container 2 of this embodiment, as... Figure 5 As shown by the dashed line, a portion of the internal electrode 32a disposed next to the opening window 81 is covered by the upper frame 11 along the length direction, so that even if the uncovered portion of the internal electrode 32a is removed by the process gas, the breakage of the internal electrode 32a can be avoided.

[0061] After the widened portion 71 of the piezoelectric vibrator 6 is ion-milled, the piezoelectric vibrator 1, which seals the piezoelectric vibrator 6 within the piezoelectric vibrator container 2, is completed by welding the sealing plate 4 to the sealing ring 13 of the piezoelectric vibrator container 2.

[0062] [Second Implementation]

[0063] Next, a second embodiment of the piezoelectric vibrator container 2 and the piezoelectric vibrator 1 will be described. In the first embodiment already described, the case where the piezoelectric vibrator 1 is formed using a piezoelectric vibrator container 2 with a length of approximately 16 mm and a width of approximately 12 mm as measured from top view was used as an example. In contrast, in the second embodiment, a piezoelectric vibrator container 2 with the same length of 16 mm as measured from top view and a narrower width of 10 mm is used. Furthermore, the piezoelectric vibrating plate 6 installed inside is the same as that described in the first embodiment.

[0064] Figure 6 This is an explanatory diagram of the piezoelectric vibrator container 2 and the piezoelectric vibrator 1 in the second embodiment. Compared with the first embodiment, it is... Figure 5 Similarly, this indicates the state of the piezoelectric vibrating plate 6 being ion-milled. For example... Figure 6As shown, in the piezoelectric vibrator container 2 of the second embodiment, the distance between the support arms 9a and 9b of the piezoelectric vibrator 6 and the inner side surface 11n of the upper frame 11 is shortened by a width reduction of 10 mm. Even in this case, the regions extending in the length direction of the internal electrodes 32a and 32b are formed in the same manner as in the first embodiment, such that a portion of their outer side in the width direction is covered by the upper frame 11, and their front ends are connected to the connecting electrodes 33a and 33b. Furthermore, a portion of the outer side of the connecting electrodes 33a and 33b is also covered by the upper frame 11 in the same manner as in the first embodiment. In the piezoelectric vibrator container 2 of the second embodiment, compared to the first embodiment, the position of the internal electrode 32a is closer to the opening window 81 for ion milling, so although the ion beam becomes easier to irradiate, a portion in the length direction is covered by the upper frame 11, thereby reliably preventing wire breakage.

[0065] In the above embodiments, the case where a portion of the width direction of the length-extending portion of the internal electrodes 32a and 32b is covered by the upper frame 11 has been described. In contrast, the portion that can be ion-irradiated by ion milling is only the internal electrode 32a extending from the internal electrode 31 toward the widening portions 71a and 71b. Therefore, the internal electrode 32b extending from the internal electrode 31 toward the side away from the widening portions 71a and 71b (the base 8 side) can also be formed such that its entire length direction is not covered by the upper frame 11.

[0066] In the described embodiments, the case where a portion of the internal electrode of the so-called side-arm type piezoelectric vibrator 6 is covered by the upper frame 11 was explained. In contrast, when a piezoelectric vibrator is installed where the base 8 is joined to the mounting portion without forming a support arm, and a single support arm is formed between the two vibrating arms 7 extending from the base 8 and joined to the mounting portion, this method is also applicable to cases where internal wiring is formed between the front ends of the vibrating arms 7a and 7b, which have a counterweight metal film for frequency adjustment, and the upper frame 11. In this case, the internal wiring is also covered by the upper frame 11 along its length, similar to the embodiment, thereby preventing breakage of the internal wiring based on ion milling.

[0067] Symbol Explanation

[0068] 1. Piezoelectric oscillator

[0069] 2 Piezoelectric Oscillator Container

[0070] 3. Concave portion

[0071] 4 Sealing plate

[0072] 6. Piezoelectric vibrating plate

[0073] 7. Vibrating arm

[0074] 71. Widening section

[0075] 8. Base

[0076] 9. Support arm section

[0077] 10. Base plate

[0078] 10f Inner surface of base plate

[0079] 10r base plate outer surface

[0080] 11. Top frame

[0081] 11n inner surface

[0082] 12 Bottom frame

[0083] 12n inner surface

[0084] 13 Sealing ring

[0085] 14 Installation Department

[0086] 15. Incision site

[0087] 21, 22, 23, 24 External electrodes

[0088] 25 Connecting electrodes

[0089] 30 Through-electrode

[0090] 31, 32 Internal electrodes

[0091] 33 Connecting electrodes

[0092] 35 Index Markers

[0093] 80 masks

[0094] 81 Open window.

Claims

1. A piezoelectric vibrator container, characterized by comprising: Possessing: a bottom plate; a ring-shaped upper frame that forms a concave portion that accommodates a piezoelectric vibration piece together with the bottom plate, and is disposed on an upper portion of the bottom plate, the piezoelectric vibration piece having a counterweight metal film for frequency adjustment formed on a tip portion of a vibration arm portion; a mounting portion formed on an inner surface of the bottom plate on a side on which the upper frame is disposed, for mounting the piezoelectric vibration piece; and a pair of internal electrodes formed on the inner surface of the bottom plate, which are electrically connected to a pair of excitation electrodes formed on the piezoelectric vibration piece via the mounting portion, of the internal electrodes, a portion on an outer side in a width direction of a portion extending in a length direction of the piezoelectric vibration piece, which is opposed to an outer side surface of the counterweight metal film, is covered by the upper frame.

2. The piezoelectric vibrator container according to claim 1, characterized in that a piezoelectric vibration piece having a pair of mounting support arm portions on both outer sides of a vibration arm portion is taken as a mounting object; a pair of the mounting portions are formed at positions corresponding to the support arm portions. of the internal electrodes, the portion in the length direction is covered by the upper frame, and a remaining portion in the length direction is exposed inside the concave portion.

3. The piezoelectric resonator container according to claim 2, characterized by of the internal electrodes, a portion in the length direction of the internal electrode that is disposed extending from the mounting portion toward the vibration arm portion side of the piezoelectric vibration piece is covered by the upper frame.

4. The piezoelectric resonator container according to claim 1, claim 2 or claim 3, characterized by, a width of the internal electrode covered by the upper frame is 1 / 3 or less of a width of the upper frame.

5. The piezoelectric resonator container according to claim 1, claim 2 or claim 3, characterized by, a width of the internal electrode covered by the upper frame is 1 / 3 or less of a width of the upper frame.

6. The piezoelectric resonator container according to claim 4, characterized by a width of the internal electrode covered by the upper frame is 1 / 4 or less of a width of the upper frame.

7. The piezoelectric resonator container according to claim 1, claim 2 or claim 3, characterized by, a width of the internal electrode covered by the upper frame is 1 / 4 or less of a width of the upper frame.

8. The piezoelectric resonator container according to claim 4, characterized by Possessing:

9. A piezoelectric vibrator characterized by comprising: the piezoelectric vibrator container according to claim 1, claim 2, or claim 3, a piezoelectric vibration piece mounted to the mounting portion, and a sealing plate connected to a surface of an open side of the concave portion, which seals and accommodates the mounted piezoelectric vibration piece inside the concave portion. Possessing:

10. A piezoelectric vibrator characterized by comprising: the piezoelectric vibrator container according to claim 4, a piezoelectric vibration piece mounted to the mounting portion, and a sealing plate connected to a surface of an open side of the concave portion, which seals and accommodates the mounted piezoelectric vibration piece inside the concave portion. ​

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