JP2024076441A - Quartz crystal wafer, piezoelectric vibrating piece, piezoelectric vibrator, and method for manufacturing the piezoelectric vibrating piece - Google Patents

Abstract

[Problem] Prevents scattering of vibrating pieces when they are broken off from a quartz crystal wafer. [Solution] A quartz crystal wafer 100 includes a piezoelectric vibrating piece 3 having a pair of vibrating arms 21, 22 extending in a longitudinal direction L, and a frame portion 50 that supports the piezoelectric vibrating piece 3 via multiple connecting portions 60, the multiple connecting portions 60 extending in a direction intersecting the longitudinal direction L. [Selected Figure] Figure 3

Description

This disclosure relates to quartz crystal wafers, piezoelectric vibrating pieces, piezoelectric vibrators, and methods for manufacturing piezoelectric vibrating pieces.

The following Patent Document 1 discloses a method for manufacturing a quartz crystal oscillator, which includes a process of breaking off each quartz crystal oscillator from a quartz crystal wafer having a large number of quartz crystal oscillators, connecting parts connecting these oscillators to a wafer, and narrow cutout parts provided near each connecting part and/or in the connecting part itself, along the Z' axis of the quartz crystal, which are integrally formed by photolithography and wet etching techniques, starting from the cutout parts.

JP 2016-32197 A

In the above-mentioned conventional technology, the quartz crystal oscillator is connected to the quartz crystal wafer at one point in the longitudinal direction along which the pair of vibrating arms of the quartz crystal oscillator extend. When breaking off this quartz crystal oscillator, a force is applied to the quartz crystal oscillator so that it bends in the thickness direction of the quartz crystal wafer, at which point tensile and compressive stresses are applied to the connecting portion. If the connecting portion breaks in this state, the quartz crystal oscillator will fly apart and may not fit into the receiver located below. Small quartz crystal oscillators in particular have a small mass and are therefore prone to flying apart when broken off, which is one of the factors that leads to reduced yields.

This disclosure was made in consideration of the above problems, and aims to prevent shattering when the vibrating piece is broken off from the quartz crystal wafer.

(1) A quartz crystal wafer according to one aspect of the present disclosure comprises a piezoelectric vibrating piece having a pair of vibrating arms extending in a longitudinal direction, and a frame portion supporting the piezoelectric vibrating piece via a plurality of connecting portions, the plurality of connecting portions extending in a direction intersecting the longitudinal direction.

In the crystal wafer according to this embodiment, the piezoelectric vibrating piece and the frame are connected by multiple connecting parts, and the multiple connecting parts extend in a direction intersecting the longitudinal direction of the piezoelectric vibrating piece. Therefore, when a force is applied to the piezoelectric vibrating piece so as to bend it in the thickness direction of the crystal wafer, a torsional moment is applied to the multiple connecting parts, and the multiple connecting parts can be broken (screwed off). This makes it easier to drop the broken piezoelectric vibrating piece vertically without scattering, increasing the storage rate in the receiver placed below and improving the yield.

(2) In the quartz crystal wafer of aspect (1), the multiple connecting portions may include a first connecting portion and a second connecting portion arranged on either side of the piezoelectric vibrating piece in the short-side direction of the piezoelectric vibrating piece.

In this case, the first connecting portion and the second connecting portion become the pivot axis when breaking off the piezoelectric vibrating piece, making it easier to twist off the piezoelectric vibrating piece.

(3) In the quartz crystal wafer of aspect (2), the first connecting portion and the second connecting portion may be connected to the piezoelectric vibrating piece at the same position in the longitudinal direction.

In this case, the breaking force due to the torsion moment is maximized when the first connecting part and the second connecting part are aligned in the same straight line, so the piezoelectric vibrating piece can be most effectively broken off in the vertical direction, and the piezoelectric vibrating piece is less likely to collide with or come into contact with the frame part when it is broken off.

(4) In the quartz crystal wafer of aspect (2), the first connecting portion and the second connecting portion may be connected to the piezoelectric vibrating piece at different positions in the longitudinal direction.

In this case, by taking into account the etching residue of the quartz crystal wafer and shifting the longitudinal positions of the first connecting part and the second connecting part, the torsional moment applied when the piezoelectric vibrating piece is broken off can be optimized, and the effects of the etching residue can be suppressed.

(5) In the quartz crystal wafer according to any one of (2) to (4), the first connecting portion and the second connecting portion may be connected to both side surfaces of the piezoelectric vibrating piece that face the short side direction.

In this case, by connecting the first and second connecting parts to both sides of the piezoelectric vibrating piece facing the short direction, the force acting when breaking the piezoelectric vibrating piece is a downward force on the piezoelectric vibrating piece, improving the storage rate in the receiver and therefore the yield.

(6) In the quartz crystal wafer of any of the aspects (2) to (4), the piezoelectric vibrating piece may have a pair of support arms that are L-shaped in a plan view and surround the pair of vibrating arms from the outside in the short side direction, the first connecting portion may be connected to one corner of the pair of support arms, and the second connecting portion may be connected to the other corner of the pair of support arms.

In this case, there is no need to extend the frame portion to both sides of the short side of the piezoelectric vibrating piece, so the piezoelectric vibrating pieces can be arranged more densely and more piezoelectric vibrating pieces can be manufactured from one quartz crystal wafer.

(7) In any of the aspects (1) to (6), the quartz crystal wafer may include an excitation electrode formed on the piezoelectric vibrating piece, and a plurality of extension electrodes extending from the excitation electrode through the plurality of connecting portions to the frame portion.

In this case, when wiring electrodes from the quartz crystal wafer to the piezoelectric vibrating piece, the electrodes can be wired through multiple routes passing through multiple connecting parts, which increases the degree of freedom in the electrode wiring structure from the quartz crystal wafer to the piezoelectric vibrating piece.

(8) In the quartz crystal wafer according to any one of (1) to (7), the multiple connecting portions may have weakened portions in which notches are formed.

In this case, the connection is more likely to break starting from the weakened area.

(9) In the quartz crystal wafer according to any one of (1) to (8), the multiple connecting portions may be wider on the frame portion side than on the piezoelectric vibrating piece side.

In this case, the connecting portion is less likely to break on the frame side, and the connecting portion is prevented from remaining on the piezoelectric vibrating piece when the piezoelectric vibrating piece is broken off.

(10) A piezoelectric vibrating piece according to one aspect of the present disclosure has a pair of vibrating arms extending in a longitudinal direction, and a plurality of break marks are formed on the side surfaces facing in a direction intersecting the longitudinal direction.

The piezoelectric vibrating piece according to this embodiment can produce high-quality piezoelectric vibrating pieces with a high yield rate.

(11) A piezoelectric vibrator according to one aspect of the present disclosure includes a piezoelectric vibrating piece according to aspect (11) and a package in which the piezoelectric vibrating piece is sealed.

The piezoelectric vibrator according to this embodiment produces high-quality piezoelectric vibrators with a high yield.

(12) A method for manufacturing a piezoelectric vibrating piece according to one aspect of the present disclosure includes a step of breaking off a piezoelectric vibrating piece from a quartz wafer having a piezoelectric vibrating piece having a pair of vibrating arms extending in a longitudinal direction and a frame portion supporting the piezoelectric vibrating piece via a plurality of connecting portions, the plurality of connecting portions extending in a direction intersecting the longitudinal direction, and the piezoelectric vibrating piece is rotated in the thickness direction of the quartz wafer around the plurality of connecting portions as fulcrums, thereby breaking the plurality of connecting portions.

The method for manufacturing piezoelectric vibrating reels according to this aspect allows for the production of high-quality piezoelectric vibrating reels with a high yield.

According to one aspect of the present disclosure, scattering of the vibrating piece when it is broken off from the quartz crystal wafer can be suppressed.

FIG. 2 is an exploded perspective view of the piezoelectric vibrator according to the first embodiment. 4 is a flowchart showing a method for manufacturing the piezoelectric vibrating piece according to the first embodiment. FIG. 2 is a plan view of the quartz crystal wafer according to the first embodiment. FIG. 2 is a plan view of the quartz crystal wafer according to the first embodiment. 4 is a plan view showing a singulation step of the method for manufacturing the piezoelectric vibrating piece according to the first embodiment; FIG. FIG. 11 is a plan view of a quartz crystal wafer according to a second embodiment. FIG. 11 is a plan view of a quartz crystal wafer according to a third embodiment. FIG. 13 is a plan view of a quartz crystal wafer according to a fourth embodiment. FIG. 13 is a plan view of a quartz crystal wafer according to a fifth embodiment. FIG. 13 is a plan view of a quartz crystal wafer according to a sixth embodiment.

[First embodiment]
Hereinafter, a first embodiment according to the present disclosure will be described with reference to the drawings.

(Piezoelectric vibrator)
FIG. 1 is an exploded perspective view of a piezoelectric vibrator 1 according to the first embodiment.
The piezoelectric vibrator 1 shown in FIG. 1 is a ceramic package type surface mount vibrator that includes a package 2 having an airtight sealed cavity 4 therein, and a tuning fork-shaped piezoelectric vibrating piece 3 housed in the cavity 4.

The piezoelectric vibrator 1 is formed in a roughly rectangular parallelepiped shape, and in this embodiment, the longitudinal direction of the piezoelectric vibrator 1 (piezoelectric vibrating piece 3) in a plan view is referred to as the length direction L, the short side direction is referred to as the width direction W, and the direction perpendicular to the length direction L and width direction W is referred to as the thickness direction T.

The package 2 comprises a package body 10 and a sealing plate 11 that is joined to the package body 10 and forms a cavity 4 between the package body 10 and the sealing plate 11.

The package body 10 includes a first base substrate 12 and a second base substrate 13 that are bonded together in a stacked state, and a seal ring 14 that is bonded onto the second base substrate 13 .
The first base substrate 12 is a ceramic substrate formed into a generally rectangular shape in a plan view. The second base substrate 13 is a ceramic substrate formed into a generally rectangular shape in a plan view, which is the same external shape as the first base substrate 12, and is bonded integrally to the first base substrate 12 by a method such as sintering while being stacked on the first base substrate 12.

At the four corners of the first base substrate 12 and the second base substrate 13, cutout portions 15 having a quarter-circular arc shape in plan view are formed over the entire thickness direction T. The first base substrate 12 and the second base substrate 13 are produced, for example, by stacking and bonding two wafer-like ceramic substrates, forming a plurality of through holes penetrating both ceramic substrates in a matrix pattern, and then cutting both ceramic substrates into a lattice pattern using each through hole as a reference. At this time, the through holes are divided into four to form the cutout portions 15.
The upper surface of the second base substrate 13 serves as a mounting surface 13a on which the piezoelectric vibrating reed 3 is mounted.

The first base substrate 12 and the second base substrate 13 are made of ceramics, and specific ceramic materials include, for example, HTCC (High Temperature Co-Fired Ceramic) made of alumina and LTCC (Low Temperature Co-Fired Ceramic) made of glass ceramics.

The seal ring 14 is a conductive frame-shaped member that is slightly smaller than the outer shape of the first base substrate 12 and the second base substrate 13, and is joined to the mounting surface 13a of the second base substrate 13. Specifically, the seal ring 14 is joined to the mounting surface 13a by baking with a brazing material such as silver brazing or a solder material, or by welding to a metal bonding layer formed on the mounting surface 13a (for example, by electrolytic plating, electroless plating, vapor deposition, sputtering, etc.).

The material of the seal ring 14 may be, for example, a nickel-based alloy, and may be selected from Kovar, Elinvar, Invar, 42-alloy, and the like. In particular, it is preferable to select a material for the seal ring 14 that has a thermal expansion coefficient close to that of the first base substrate 12 and the second base substrate 13, which are made of ceramic. For example, if alumina with a thermal expansion coefficient of 6.8×10-6/°C is used for the first base substrate 12 and the second base substrate 13, it is preferable to use Kovar with a thermal expansion coefficient of 5.2×10-6/°C or 42-alloy with a thermal expansion coefficient of 4.5 to 6.5×10-6/°C for the seal ring 14.

The sealing plate 11 is a conductive substrate layered on the seal ring 14, and is hermetically bonded to the package body 10 by bonding to the seal ring 14. The space defined by the sealing plate 11, the seal ring 14, and the mounting surface 13a of the second base substrate 13 functions as a hermetically sealed cavity 4.

Methods for welding the sealing plate 11 include, for example, seam welding by contacting a roller electrode, laser welding, ultrasonic welding, etc. In order to ensure a more reliable welding between the sealing plate 11 and the seal ring 14, it is preferable to form a bonding layer of nickel or gold, which has good compatibility with each other, at least on the lower surface of the sealing plate 11 and the upper surface of the seal ring 14.

A pair of electrode pads 16a, 16b, which are connection electrodes with the piezoelectric vibrating piece 3, are formed on the mounting surface 13a of the second base substrate 13 with a gap in the width direction W. A pair of external electrodes 17a, 17b are formed on the lower surface of the first base substrate 12 with a gap in the length direction L. These electrode pads 16a, 16b and external electrodes 17a, 17b are single-layer films made of a single metal formed by, for example, vapor deposition or sputtering, or laminated films in which different metals are laminated, and are mutually conductive.

That is, the first base substrate 12 and the second base substrate 13 are formed with conductive electrodes (not shown) that connect one electrode pad 16a and one external electrode 17a. The first base substrate 12 and the second base substrate 13 are also formed with conductive electrodes (not shown) that connect the other electrode pad 16b and the other external electrode 17b. These conductive electrodes extend in the thickness direction T in the first base substrate 12 and the second base substrate 13, and extend in the planar direction (direction including the length direction L and width direction W) between the first base substrate 12 and the second base substrate 13.

A recess 19 is formed on the mounting surface 13a of the second base substrate 13 in a portion facing the piezoelectric vibrating piece 3 to avoid contact with the piezoelectric vibrating piece 3 when the pair of vibrating arms 21, 22, etc. are displaced (flexed) in the thickness direction T due to the impact of a fall or other impact. This recess 19 is a through hole that penetrates the second base substrate 13, and is formed inside the seal ring 14 in a square shape in plan view with rounded corners. A pair of electrode pads 16a, 16b are formed on a pair of protrusions 13b that protrude inward in the width direction W from both side surfaces of the recess 19 in the width direction W.

The piezoelectric vibrating piece 3 is mounted via metal bumps or conductive adhesive (not shown) so that a pair of mounting electrodes on a pair of support arms 23, 24 formed on the base 20 contact the pair of electrode pads 16a, 16b. As a result, the piezoelectric vibrating piece 3 is supported in a floating state above the mounting surface 13a of the second base substrate 13 and is electrically connected to the pair of electrode pads 16a, 16b, respectively.

(Piezoelectric vibrating piece)
The piezoelectric vibrating piece 3 is a tuning fork-shaped vibrating piece made of a piezoelectric material such as quartz crystal, lithium tantalate, or lithium niobate, and vibrates when a predetermined voltage is applied.
The piezoelectric vibrating piece 3 includes a base 20 and a pair of vibrating arms 21 and 22 .

The pair of vibrating arms 21, 22 extend parallel to each other from the base 20 along the length direction L. The tip side of the pair of vibrating arms 21, 22 in the extension direction is a free end that vibrates with the base end side (base 20 side) as a fixed end. The pair of vibrating arms 21, 22 are of a hammerhead type in which the width dimension of the tip side is larger than that of the base end side.

When the pair of vibrating arms 21, 22 are of the hammerhead type, the weight of the tip side of the vibrating arms 21, 22 and the moment of inertia during vibration can be increased, making it easier for the vibrating arms 21, 22 to vibrate. This has the advantage that the length of the vibrating arms 21, 22 can be shortened, resulting in a smaller size.

The pair of vibrating arms 21, 22 each have a groove 25 formed on both surfaces in the thickness direction T along the length direction L (extension direction) of the pair of vibrating arms 21, 22. The groove 25 is formed, for example, between the base end side and the tip end side of the pair of vibrating arms 21, 22.
Further, the pair of vibrating arms 21 and 22 are provided with two systems of excitation electrodes which are insulated from each other and vibrate the vibrating arms 21 and 22 in the width direction W.

The base 20 integrally connects the base ends of the pair of vibrating arms 21, 22. The base 20 also has a pair of support arms 23, 24 formed thereon. The pair of support arms 23, 24 are L-shaped in a plan view and surround the pair of vibrating arms 21, 22 from the outside in the width direction W. Specifically, the pair of support arms 23, 24 protrude outward in the width direction W and then extend parallel to the pair of vibrating arms 21, 22 along the length direction L.

When operating the piezoelectric vibrator 1 configured in this manner, a predetermined drive voltage is applied to the pair of external electrodes 17a, 17b. This allows current to flow through the pair of electrode pads 16a, 16b to the excitation electrodes of the pair of vibrating arms 21, 22 of the piezoelectric vibrating piece 3. The interaction between these excitation electrodes causes the pair of vibrating arms 21, 22 to vibrate at a predetermined resonant frequency in the direction in which they approach and move away from each other (width direction W). The vibration of the pair of vibrating arms 21, 22 can be used as a time source, a timing source for a control signal, a reference signal source, etc.

In this embodiment, a ceramic package type surface mount type vibrator has been described as the piezoelectric vibrator 1 using the piezoelectric vibrating piece 3, but the piezoelectric vibrating piece 3 can also be applied to a glass package type piezoelectric vibrator 1 in which a base substrate and a lid substrate made of glass material are joined by anodic bonding.

In addition, in this embodiment, a piezoelectric vibrating piece 3 is used in which grooves 25 are formed in a pair of vibrating arms 21, 22, but a piezoelectric vibrating piece without grooves 25 may also be used.

(Manufacturing method of piezoelectric vibrating piece)
FIG. 2 is a flowchart showing a method for manufacturing the piezoelectric vibrating reed 3 according to the first embodiment.
As shown in FIG. 2, the piezoelectric vibrating piece 3 is manufactured through an outer shape forming process (step S10), an electrode forming process (step S20), a weight metal film forming process (step S30), a frequency adjustment process (step S40), and a singulation process (step S50).

The outline forming process is a process for cutting out the outline of the piezoelectric vibrating piece 3 from the quartz wafer. In the outline forming process, if the piezoelectric vibrating piece 3 does not have a groove portion 25, a protective film is formed on the surface of the quartz wafer by metal sputtering, and a photoresist film corresponding to the outline shape of the piezoelectric vibrating piece 3 is patterned on the protective film by photolithography. Then, metal etching is performed using this photoresist film as a mask, and the unmasked protective film is selectively removed. Thereafter, the portions from which the protective film has been removed are etched, allowing the outline of the piezoelectric vibrating piece 3 to be cut out from the quartz wafer.

If the piezoelectric vibrating piece 3 has a groove 25, a photoresist film is formed on the patterned etching protective film, as in the outer shape formation described above. Then, the photoresist film is patterned by photolithography to open the area of the groove 25. Then, etching is performed using the patterned photoresist film as a mask, and the etching protective film is selectively removed. After that, by removing the photoresist film, the already patterned etching protective film can be further patterned while leaving the area of the groove 25 open. Next, the quartz wafer is etched using this re-patterned etching protective film as a mask, and the etching protective film that was used as a mask is removed. This allows the groove 25 to be formed on both main surfaces of the pair of vibrating arms 21 and 22.

The electrode formation process is a process in which electrodes are formed on the piezoelectric vibrating piece 3 after the external shape formation process. In the electrode formation process, an electrode film is formed on the surface of the piezoelectric vibrating piece 3 by metal sputtering, and a photoresist film corresponding to a predetermined electrode shape is patterned on the electrode film by photolithography. Then, metal etching is performed using this photoresist film as a mask, and the unmasked electrode film is selectively removed. This allows electrodes to be formed on the piezoelectric vibrating piece 3.

The weight metal film formation process is a process in which a metal film that acts as a weight for adjusting the frequency is vapor-deposited on the pair of vibrating arms 21 and 22 of the piezoelectric vibrating piece 3 after the electrode formation process. The weight metal film formation process may be performed simultaneously with the electrode formation process.

The frequency adjustment process is a process for adjusting the frequency of the piezoelectric vibrating piece 3 after the weight metal film formation process. In the frequency adjustment process, a driving voltage is applied to the piezoelectric vibrating piece 3 by pressing a probe of a measuring device against it, causing the pair of vibrating arms 21, 22 to vibrate. Then, depending on the difference between the frequency measured at this time and a preset target frequency, the weights evaporated onto the pair of vibrating arms 21, 22 are partially removed by laser trimming or the like. This allows the frequency of the piezoelectric vibrating piece 3 to be adjusted to the target frequency.

The singulation process is a process in which the piezoelectric vibrating pieces 3 are broken off from the quartz crystal wafer to separate the piezoelectric vibrating pieces 3. As shown in FIG. 1, the singulated piezoelectric vibrating pieces 3 have a first break mark 26A and a second break mark 26B formed on the side surfaces facing the width direction W.

The first break mark 26A and the second break mark 26B have cut surfaces formed by a surface (non-crystalline surface) having a structure different from the natural crystal surface of quartz, and are, for example, uneven surfaces having wavy irregularities. The first break mark 26A is formed on the side surface of the piezoelectric vibrating piece 3 on the support arm 23 side in the width direction W. The second break mark 26B is formed on the side surface of the piezoelectric vibrating piece 3 on the support arm 24 side in the width direction W.
In this manner, the piezoelectric vibrating reed 3 can be manufactured.

(quartz crystal wafer)
Fig. 3 is a plan view of the crystal wafer 100 according to the first embodiment. Note that Fig. 3 shows the crystal wafer 100 after the above-mentioned outer shape forming process. Note that the reference character C in Fig. 3 indicates a center line C passing through the center positions of the pair of vibrating arms 21, 22 of the piezoelectric vibrating piece 3.
As shown in FIG. 3, the quartz crystal wafer 100 includes a piezoelectric vibrating piece 3 and a frame portion 50 that supports the piezoelectric vibrating piece 3 via a plurality of connecting portions 60 .

The frame portion 50 is formed in a rectangular frame shape surrounding the piezoelectric vibrating piece 3. The frame portion 50 includes a first portion 51 extending in the width direction W along the base portion 20 of the piezoelectric vibrating piece 3, a second portion 52 and a third portion 53 extending in the length direction L along a pair of support arms 23, 24 of the piezoelectric vibrating piece 3, and a fourth portion 54 extending in the width direction W along the tips of the pair of vibrating arms 21, 22 of the piezoelectric vibrating piece 3.

The connecting portion 60 includes a first connecting portion 60A and a second connecting portion 60B. The first connecting portion 60A and the second connecting portion 60B each extend in a direction intersecting the length direction L (in this embodiment, the width direction W) and are connected to the base portion 20 of the piezoelectric vibrating piece 3. The first connecting portion 60A has a first weakened portion 61A in which a notch is formed. The second connecting portion 60B has a second weakened portion 61B in which a notch is formed.

The notches formed in the first weakened portion 61A and the second weakened portion 61B are formed, for example, by etching in the contour forming process. The first connecting portion 60A and the second connecting portion 60B can be broken off starting from the first weakened portion 61A and the second weakened portion 61B. In other words, the break mark of the first weakened portion 61A is the first break mark 26A shown in FIG. 1, and the break mark of the second weakened portion 61B is the second break mark 26B shown in FIG. 1.

As shown in FIG. 3, the first connecting portion 60A extends in the width direction W from the second portion 52 of the frame portion 50 and is connected to the side surface of the piezoelectric vibrating piece 3 on the support arm portion 23 side. The first connecting portion 60A is wider on the frame portion 50 side than on the piezoelectric vibrating piece 3 side. Specifically, the first connecting portion 60A has a first width W1 on the frame portion 50 side, and a second width W2 smaller than the first width W1 on the piezoelectric vibrating piece 3 side. Furthermore, the first connecting portion 60A has a third width W3 smaller than the second width W2 at the first weakened portion 61A located at the end on the piezoelectric vibrating piece 3 side.

The first connecting portion 60A has a dimension in the width direction W that gradually decreases from a first width W1 to a second width W2 from the frame portion 50 side to the first weakened portion 61A on the piezoelectric vibrating piece 3 side. More specifically, the slope at which the width of the first connecting portion 60A decreases gradually decreases from the frame portion 50 side toward the piezoelectric vibrating piece 3 side. As a result, both side surfaces in the width direction W of the first connecting portion 60A are curved. At the first weakened portion 61A, the first connecting portion 60A is locally constricted (notched), and the first connecting portion 60A has a minimum width.

The second connecting portion 60B is disposed opposite the first connecting portion 60A in the width direction W, sandwiching the piezoelectric vibrating piece 3 therebetween. In other words, the first connecting portion 60A and the second connecting portion 60B are connected to the piezoelectric vibrating piece 3 at the same position in the length direction L. The connecting positions in the length direction L of the first connecting portion 60A and the second connecting portion 60B are preferably on the base end side rather than the tip side of the piezoelectric vibrating piece 3. The second connecting portion 60B extends in the width direction W from the third portion 53 of the frame portion 50, and is connected to the side surface of the piezoelectric vibrating piece 3 on the support arm portion 24 side. Like the first connecting portion 60A, the second connecting portion 60B is wider on the frame portion 50 side than on the piezoelectric vibrating piece 3 side.

The first weakened portion 61A and the second weakened portion 61B are locally narrowed in width, but essentially, it is sufficient to reduce the rigidity of the connecting portion 60, and for example, the thickness of the connecting portion 60 may be locally thinned. Also, the first weakened portion 61A and the second weakened portion 61B may be formed by, for example, forming micropores (fine holes) by laser irradiation or a chemical solution, etc., so as to locally reduce the rigidity of the connecting portion 60.

Fig. 4 is a plan view of the quartz-crystal wafer 100 according to the first embodiment. Fig. 4 shows the quartz-crystal wafer 100 after the electrode formation process.
4, two systems of electrodes 30, 40 are formed on the piezoelectric vibrating piece 3. The pair of vibrating arms 21, 22 include arm portions 21a, 22a extending from the base portion 20 in the longitudinal direction L, and head portions 21b, 22b connected to the tips of the arm portions 21a, 22a.

Excitation electrodes 31, 41 are formed on the outer surfaces of the arm portions 21a, 22a. When a predetermined drive voltage is applied, the excitation electrodes 31, 41 vibrate the pair of vibrating arms 21, 22 in the width direction W. The excitation electrodes 31, 41 are patterned in a state where they are electrically insulated from each other.

Weight metal films 32, 42 are formed on the outer surfaces of the head portions 21b, 22b. The weight metal films 32, 42 are provided to increase the mass at the tips of the pair of vibrating arms 21, 22 and suppress an increase in the resonant frequency when the pair of vibrating arms 21, 22 are shortened. In this embodiment, the weight metal film 32 is formed integrally with the excitation electrode 31, and the weight metal film 42 is formed integrally with the excitation electrode 41.

Mount electrodes 33, 43 are provided on the outer surfaces of the pair of support arms 23, 24 as mounts when mounting the piezoelectric vibrating piece 3 to the package 2. Specifically, the mount electrode 33 is formed on one of the pair of support arms 23, 24, the support arm 24. The mount electrode 43 is formed on the other of the pair of support arms 23, 24, the support arm 23.

The excitation electrodes 31, 41 and the mount electrodes 33, 43 are respectively connected by lead-out electrodes 34, 44. The lead-out electrode 34 is formed on a path that extends from the support arm 24 through the base 20 to the vibrating arm 22. The lead-out electrode 44 is formed on a path that extends from the support arm 23 through the base 20 to the vibrating arm 21.
The excitation electrodes 31, 41, the mount electrodes 33, 43, and the lead-out electrodes 34, 44 are formed on both main surfaces of the piezoelectric vibrating reed 3 so that their planar shapes when viewed from the thickness direction T are the same, for example.

On the main surface of the base 20, the extension electrodes 35, 45 are formed, which extend through the connecting portion 60 to the frame portion 50. The extension electrode 35 extends from the wiring electrode 34 through the second connecting portion 60B to the frame portion 50. The extension electrode 45 extends from the wiring electrode 44 through the first connecting portion 60A to the frame portion 50. This allows the electrode to be routed through two routes, the first connecting portion 60A and the second connecting portion 60B, when wiring the electrode from the frame portion 50 to the piezoelectric vibrating piece 3. If there is only one connecting portion 60, for example, it is necessary to form the electrode 30 on one main surface of the connecting portion 60 and the electrode 40 on the other main surface of the connecting portion 60 to wire the electrode.

In the frequency adjustment process, the probe of the measuring device is pressed against the electrodes 30, 40 on the frame portion 50, and a predetermined drive voltage is applied between the excitation electrodes 31, 41 via the extension electrodes 35, 45, causing the pair of vibrating arms 21, 22 to vibrate. This makes it possible to measure the frequency of the piezoelectric vibrating piece 3. Then, after the frequency adjustment process, the piezoelectric vibrating piece 3 is broken off from the quartz crystal wafer 100 in the singulation process.

FIG. 5 is a plan view showing a singulation step in the method for manufacturing the piezoelectric vibrating reed according to the first embodiment.
As shown in FIG. 5, in the singulation process, for example, the tip side area A on the groove portion 25 of the pair of vibrating arms 21, 22 is pressed in the thickness direction T by a breaking tool (not shown). Then, the piezoelectric vibrating piece 3 rotates in the thickness direction T of the crystal wafer 100 with the first connecting portion 60A and the second connecting portion 60B as a fulcrum, and the first connecting portion 60A and the second connecting portion 60B are broken so as to be twisted off starting from the first weakened portion 61A and the second weakened portion 61B. As a result, as shown in FIG. 1, the first breaking mark 26A is formed in the portion corresponding to the first connecting portion 60A, and the second breaking mark 26B is formed in the portion corresponding to the second connecting portion 60B. Note that since the first breaking mark 26A and the second breaking mark 26B are formed in the pair of supporting arms 23, 24, even if the breaking marks remain, they do not affect the product characteristics.

As described above, the crystal wafer 100 of this embodiment includes a piezoelectric vibrating piece 3 having a pair of vibrating arms 21, 22 extending in the length direction L (longitudinal direction), and a frame portion 50 that supports the piezoelectric vibrating piece 3 via a plurality of connecting portions 60, the plurality of connecting portions 60 extending in a direction intersecting the length direction L.

According to the crystal wafer 100 of this embodiment, the piezoelectric vibrating piece 3 and the frame portion 50 are connected by multiple connecting portions 60, and the multiple connecting portions 60 extend in a direction intersecting the length direction L of the piezoelectric vibrating piece 3. Therefore, when a force is applied to the piezoelectric vibrating piece 3 so as to bend it in the thickness direction T of the crystal wafer 100, a torsional moment is applied to the multiple connecting portions 60, and the multiple connecting portions 60 can be broken (screwed off). This makes it easier to drop the broken piezoelectric vibrating pieces 3 vertically without scattering them, increasing the storage rate in a receiver (not shown) located below and improving yield.

In addition, in the crystal wafer 100 of this embodiment, the multiple connecting parts 60 include a first connecting part 60A and a second connecting part 60B arranged on either side of the piezoelectric vibrating piece 3 in the width direction W (short side direction) of the piezoelectric vibrating piece 3. With this configuration, the first connecting part 60A and the second connecting part 60B become the rotation axis when breaking off the piezoelectric vibrating piece 3, making it easier to twist off the piezoelectric vibrating piece 3.

In addition, in the crystal wafer 100 of this embodiment, the first connecting portion 60A and the second connecting portion 60B are connected to the piezoelectric vibrating piece 3 at the same position in the longitudinal direction L. With this configuration, the breaking force due to the torsion moment is maximized when the first connecting portion 60A and the second connecting portion 60B are on the same straight line, so that the piezoelectric vibrating piece 3 can be most effectively broken off in the vertical direction, and the piezoelectric vibrating piece 3 is less likely to collide with or come into contact with the frame portion 50 when breaking off the piezoelectric vibrating piece 3.

In addition, in the crystal wafer 100 of this embodiment, the first connecting portion 60A and the second connecting portion 60B are connected to both side surfaces of the piezoelectric vibrating piece 3 facing the width direction W. With this configuration, by connecting the first connecting portion 60A and the second connecting portion 60B to both side surfaces of the piezoelectric vibrating piece 3 in the width direction W, the force when the piezoelectric vibrating piece 3 is broken becomes a downward force against the piezoelectric vibrating piece 3, improving the storage rate in a receiver not shown, and therefore improving the yield.

In addition, the crystal wafer 100 of this embodiment includes excitation electrodes 31, 41 formed on the piezoelectric vibrating piece 3, and extension electrodes 35, 45 extending from the excitation electrodes 31, 41 through multiple connecting parts 60 to the frame part 50, and includes an extension electrode 45 (first extension electrode) passing through the first connecting part 60A and an extension electrode 35 (second extension electrode) passing through the second connecting part 60B. With this configuration, when the electrodes are routed from the crystal wafer 100 to the piezoelectric vibrating piece 3, the electrodes can be routed through two routes, the first connecting part 60A and the second connecting part 60B, so that the degree of freedom of the electrode routing structure from the crystal wafer 100 to the piezoelectric vibrating piece 3 is increased.

In addition, in the quartz crystal wafer 100 of this embodiment, the multiple connecting portions 60 have a first weakened portion 61A and a second weakened portion 61B in which a notch is formed. This configuration makes it easier to break the connecting portions 60 starting from the first weakened portion 61A and the second weakened portion 61B.

In addition, in the crystal wafer 100 of this embodiment, the multiple connecting portions 60 are wider on the frame portion 50 side than on the piezoelectric vibrating piece 3 side. This configuration makes it difficult for the connecting portions 60 to break on the frame portion 50 side, and prevents the connecting portions 60 from remaining on the piezoelectric vibrating piece 3 side when the piezoelectric vibrating piece 3 is broken off.

The piezoelectric vibrating piece 3 of this embodiment has a pair of vibrating arms 21, 22 extending in the longitudinal direction L, and has multiple break marks (first break mark 26A and second break mark 26B) formed on the side surface facing a direction intersecting the longitudinal direction L. According to the piezoelectric vibrating piece 3 of this embodiment, a high-quality piezoelectric vibrating piece 3 with a high yield can be obtained.

The piezoelectric vibrator 1 of this embodiment also includes a piezoelectric vibrating piece 3 and a package in which the piezoelectric vibrating piece 3 is sealed. With the piezoelectric vibrator 1 of this embodiment, a high-quality piezoelectric vibrator 1 with a high yield can be obtained.

The method for manufacturing the piezoelectric vibrating piece 3 of this embodiment includes a step of breaking off the piezoelectric vibrating piece 3 from a crystal wafer 100 having a piezoelectric vibrating piece 3 having a pair of vibrating arm portions 21, 22 extending in the length direction L and a frame portion 50 supporting the piezoelectric vibrating piece 3 via a plurality of connecting portions 60, the plurality of connecting portions 60 extending in a direction intersecting the length direction L, and the piezoelectric vibrating piece 3 is rotated in the thickness direction T of the crystal wafer 100 with the plurality of connecting portions 60 as fulcrums, thereby breaking the plurality of connecting portions 60. According to the method for manufacturing the piezoelectric vibrating piece 3 of this embodiment, it is possible to manufacture high-quality piezoelectric vibrating pieces 3 with a high yield.

In this way, according to this embodiment, scattering of the vibrating piece when it is broken off from the quartz crystal wafer 100 can be suppressed, and high-quality piezoelectric vibrating pieces 3 and piezoelectric vibrators 1 can be manufactured with a high yield.

[Second embodiment]
Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

FIG. 6 is a plan view of a quartz-crystal wafer 100 according to the second embodiment.
As shown in Figure 6, the quartz crystal wafer 100 of the second embodiment differs from the above embodiment in that the first connecting portion 60A and the second connecting portion 60B are connected to the piezoelectric vibrating piece 3 at different positions in the longitudinal direction L.

That is, the center line C1 extending in the width direction W of the first connecting portion 60A is separated from the center line C2 extending in the width direction W of the second connecting portion 60B by a distance D in the length direction L. Note that in the example of FIG. 6, the connecting position of the second connecting portion 60B is set closer to the base end side of the piezoelectric vibrating piece 3 than the connecting position of the first connecting portion 60A, but the positional relationship may be reversed.

In this way, in the crystal wafer 100 of the second embodiment, the first connecting portion 60A and the second connecting portion 60B are connected to the piezoelectric vibrating piece 3 at different positions in the length direction L. With this configuration, by taking into account the etching residue of the crystal wafer 100 and shifting the positions of the first connecting portion 60A and the second connecting portion 60B in the length direction L, it is possible to optimize the torsional moment applied when the piezoelectric vibrating piece 3 is broken off, and to suppress the effects of the etching residue.

[Third embodiment]
Next, a third embodiment of the present invention will be described. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

FIG. 7 is a plan view of a quartz-crystal wafer 100 according to the third embodiment.
As shown in FIG. 7, the quartz crystal wafer 100 according to the third embodiment differs from the above-described embodiments in that the width of the connecting portion 60 narrows seamlessly from the frame portion 50 side to the piezoelectric vibrating reed 3 side.

Specifically, the first connecting portion 60A has a dimension in the width direction W that gradually decreases from a first width W1 to a fourth width W4 from the frame portion 50 side to the first weakened portion 61A on the piezoelectric vibrating piece 3 side. The fourth width W4 is the same as or slightly larger than the third width W3 of the first weakened portion 61A. The width of the second connecting portion 60B also changes in the same way as the first connecting portion 60A.

In this way, in the quartz crystal wafer 100 of the third embodiment, the width of the connecting portion 60 narrows seamlessly from the frame portion 50 side to the piezoelectric vibrating piece 3 side, so that, for example, it is possible to simplify or omit the process of forming a notch in the connecting portion 60.

[Fourth embodiment]
Next, a fourth embodiment of the present invention will be described. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

FIG. 8 is a plan view of a quartz-crystal wafer 100 according to the fourth embodiment.
8, the quartz crystal wafer 100 according to the fourth embodiment differs from the above-mentioned embodiment in that the widths of the first connecting portion 60A and the second connecting portion 60B are constant except for the first weakened portion 61A and the second weakened portion 61B. Also, the quartz crystal wafer 100 according to the fourth embodiment differs from the above-mentioned embodiment in that the connecting positions of the first connecting portion 60A and the second connecting portion 60B are set on the base portion 20 side of the piezoelectric vibrating piece 3.

Specifically, the first connecting portion 60A has a fifth width W5 from the frame portion 50 side to the first weakened portion 61A on the piezoelectric vibrating reed 3 side. In other words, the first connecting portion 60A has a constant width from the frame portion 50 side to the first weakened portion 61A on the piezoelectric vibrating reed 3 side, and the first weakened portion 61A is locally narrowed (cut out) to have the smallest width. The width of the second connecting portion 60B also changes in the same way as the first connecting portion 60A. With this configuration, the shape of the connecting portion 60 is simplified and the forming of the connecting portion 60 becomes easier.

In addition, in the quartz crystal wafer 100 of the fourth embodiment, the connection positions of the first connecting portion 60A and the second connecting portion 60B are set on the base 20 side of the piezoelectric vibrating piece 3. With this configuration, the connection positions of the first connecting portion 60A and the second connecting portion 60B are farther away from the tip side region A shown in FIG. 5, so that a large moment is generated when breaking off the piezoelectric vibrating piece 3, making it easier to break off the piezoelectric vibrating piece 3.

[Fifth embodiment]
Next, a fifth embodiment of the present invention will be described. In the following description, the same or equivalent components as those in the above-described embodiment are denoted by the same reference numerals, and the description thereof will be simplified or omitted.

FIG. 9 is a plan view of a quartz-crystal wafer 100 according to the fifth embodiment.
As shown in FIG. 9 , the crystal wafer 100 according to the fifth embodiment differs from the above-described embodiments in that the frame portion 50 does not include the second portion 52 , part of the third portion 53 , and the fourth portion 54 .

Specifically, the frame portion 50 does not have any portion beyond the first connecting portion 60A and the second connecting portion 60B of the second portion 52 and the third portion 53. This configuration makes it possible to avoid collision or contact between the frame portion 50 and a breaking tool (not shown).

Sixth Embodiment
Next, a sixth embodiment of the present invention will be described. In the following description, the same reference numerals are used to designate the same or equivalent components as those in the above-described embodiment, and the description thereof will be simplified or omitted.

FIG. 10 is a plan view of a quartz-crystal wafer 100 according to the sixth embodiment.
As shown in Figure 10, the quartz crystal wafer 100 of the sixth embodiment differs from the above embodiments in that the first connecting portion 60A is connected to a corner of one of the pair of support arms 23, 24 (support arm 23), and the second connecting portion 60B is connected to a corner of the other of the pair of support arms 23, 24 (support arm 24).

Specifically, the frame portion 50 includes a fifth portion 55 and a sixth portion 56 extending parallel to the length direction L from the first portion 51. A first connecting portion 60A is provided at the tip of the fifth portion 55 and is connected to a corner of the support arm portion 23 of the piezoelectric vibrating piece 3. The first connecting portion 60A in this example corresponds to the first weakened portion 61A in which a notch is formed, and its center line C1 extends in a diagonal direction with respect to the length direction L. A second connecting portion 60B is provided at the tip of the sixth portion 56 and is connected to a corner of the support arm portion 24 of the piezoelectric vibrating piece 3. The second connecting portion 60B in this example corresponds to the second weakened portion 61B in which a notch is formed, and its center line C2 extends in a diagonal direction with respect to the length direction L.

Thus, in the crystal wafer 100 of the sixth embodiment, the piezoelectric vibrating piece 3 has a pair of support arms 23, 24 that are L-shaped in plan view and surround the pair of vibrating arms 21, 22 from the outside in the width direction W, and the first connecting portion 60A is connected to a corner of one of the pair of support arms 23, 24 (support arm 23), and the second connecting portion 60B is connected to a corner of the other of the pair of support arms 23, 24 (support arm 24). With this configuration, it is no longer necessary to extend the frame portion 50 (the second portion 52 and the third portion 53 described above) to both sides of the width direction W of the piezoelectric vibrating piece 3, so that the piezoelectric vibrating pieces 3 can be densely arranged as shown in FIG. 10, and more piezoelectric vibrating pieces 3 can be manufactured from one crystal wafer 100.

While preferred embodiments of the present invention have been described and illustrated above, it should be understood that these disclosures are illustrative of the present invention and should not be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present invention. Accordingly, the present invention should not be considered as limited by the foregoing description, but rather by the scope of the appended claims.

For example, in the above embodiment, the piezoelectric vibrating piece 3 is a so-called side arm type having a pair of support arms 23, 24 (side arms) extending from the base 20, but it may have no side arms. In this case, the piezoelectric vibrating piece 3 may be mounted in the package 2 using the base 20 as a mount.

For example, in the above embodiment, the first connecting portion 60A and the second connecting portion 60B are exemplified as the multiple connecting portions 60, but as long as the first connecting portion 60A and the second connecting portion 60B are included, a third connecting portion, a fourth connecting portion, etc. may also be included.

1...piezoelectric vibrator, 2...package, 3...piezoelectric vibrating piece, 4...cavity, 10...package body, 11...sealing plate, 12...first base substrate, 13...second base substrate, 13a...mounting surface, 13b...protrusion, 14...seal ring, 15...notch, 16a...electrode pad, 16b...electrode pad, 17a...external electrode, 17b...external electrode, 19...recess, 20...base, 21...vibrating arm, 21a...arm, 21b...head, 22...vibrating arm, 22a...arm, 22b...head, 23...support arm, 24...support arm, 25...groove, 26A...first break mark, 26B...second break mark, 30...electrode, 31...excitation electrode, 32...metal film, 33...mount electrode, 34...routing Electrode, 35...extended electrode (second extended electrode), 40...electrode, 41...excitation electrode, 42...metal film, 43...mount electrode, 44...drawing electrode, 45...extended electrode (first extended electrode), 50...frame portion, 51...first portion, 52...second portion, 53...third portion, 54...fourth portion, 55...fifth portion, 56...sixth portion, 60...connecting portion, 60A...first connecting portion, 60B...second connecting portion, 61A...first weakened portion, 61B...second weakened portion, 100...quartz crystal wafer, A...tip side region, C...center line, C1...center line, C2...center line, D...distance, L...length direction (longitudinal direction), T...thickness direction, W...width direction (shortitudinal direction), W1...first width, W2...second width, W3...third width, W4...fourth width, W5...fifth width

Claims (12)

A piezoelectric vibrating piece having a pair of vibrating arms extending in a longitudinal direction;
a frame portion that supports the piezoelectric vibrating piece via a plurality of connecting portions,
The plurality of connecting portions extend in a direction intersecting the longitudinal direction.
Quartz crystal wafer. The plurality of connecting portions include a first connecting portion and a second connecting portion arranged on either side of the piezoelectric vibrating piece in a short-side direction of the piezoelectric vibrating piece.
The quartz crystal wafer according to claim 1 . The first connecting portion and the second connecting portion are connected to the piezoelectric vibrating piece at the same position in the longitudinal direction.
The quartz crystal wafer according to claim 2 . The first connecting portion and the second connecting portion are connected to the piezoelectric vibrating piece at different positions in the longitudinal direction.
The quartz crystal wafer according to claim 2 . The first connecting portion and the second connecting portion are connected to both side surfaces of the piezoelectric vibrating piece facing the short side direction.
The quartz crystal wafer according to claim 2 . the piezoelectric vibrating piece has a pair of support arms that are L-shaped in a plan view and surround the pair of vibrating arms from the outside in the short side direction,
The first connecting portion is connected to one corner of the pair of support arms,
The second connecting portion is connected to the other corner portion of the pair of support arms.
The quartz crystal wafer according to claim 2 . An excitation electrode formed on the piezoelectric vibrating piece;
A plurality of extension electrodes extending from the excitation electrode through the plurality of connecting portions to the frame portion,
The quartz crystal wafer according to any one of claims 1 to 6. The plurality of connecting portions have weakened portions in which notches are formed.
The quartz crystal wafer according to any one of claims 1 to 6. The plurality of connecting portions are wider on the frame portion side than on the piezoelectric vibrating piece side.
The quartz crystal wafer according to any one of claims 1 to 6. A pair of vibrating arms extending in a longitudinal direction are provided.
A plurality of break marks are formed on a side surface facing a direction intersecting the longitudinal direction,
Piezoelectric vibrating piece. The piezoelectric vibrating piece according to claim 10,
and a package in which the piezoelectric vibrating piece is sealed.
Piezoelectric vibrator. A method for manufacturing a piezoelectric vibrating piece, comprising: a step of breaking off a piezoelectric vibrating piece from a quartz crystal wafer including a piezoelectric vibrating piece having a pair of vibrating arms extending in a longitudinal direction and a frame portion supporting the piezoelectric vibrating piece via a plurality of connecting portions;
The plurality of connecting portions extend in a direction intersecting the longitudinal direction,
The piezoelectric vibrating piece is rotated in a thickness direction of the quartz crystal wafer with the plurality of connecting portions as fulcrums, thereby breaking the plurality of connecting portions.
A method for manufacturing a piezoelectric vibrating piece.

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