JP2009239731A - Piezoelectric oscillation device, tuning-fork piezoelectric vibration piece, and method for manufacturing tuning-fork piezoelectric vibration piece - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adjust an oscillation frequency without removing a metal film from a side surface of an edge portion. <P>SOLUTION: A method for adjusting a crystal vibration piece 3 includes adjusting the oscillation frequency in a wafer 6 on which a plurality of the crystal vibration pieces 3 are formed. The crystal vibration piece 3 disclosed herein includes a base portion 31 and two leg portions 32, 33 projected from the base portion 31. The method of adjusting the crystal vibration piece 3 includes the steps of forming metal films 5 on side surfaces 34 of edge portions 37 of leg portions 32, 33 of the crystal vibration piece 3 to carry out shift adjustment of the oscillation frequency in the wafer 6 on which the plurality of the crystal vibration pieces 3 are formed, forming the metal films 5 on the main surfaces 35 of the edge portions 37 of the leg portions 32, 33 of the crystal vibration piece 3 to remove only the required amount of the formed metal films 5 by a metal film removing means, and carrying out variation of the oscillation frequency of the plurality of the crystal vibration pieces 3 in the wafer 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a piezoelectric vibrating device, a tuning fork type piezoelectric vibrating piece, and a method for manufacturing a tuning fork type piezoelectric vibrating piece, and more particularly to a frequency adjusting method for a tuning fork type piezoelectric vibrating piece.

  As one of the production processes of the tuning fork type piezoelectric vibrator, there is an oscillation frequency adjustment process (see, for example, Patent Document 1).

In the tuning fork type piezoelectric vibrator described in Patent Document 1 described below, a tuning fork type piezoelectric vibrating piece is provided in the hermetically sealed internal space. This tuning fork-type piezoelectric vibrating piece includes a base and two legs. Excitation electrodes having different polarities on both main surfaces and both side surfaces are formed on each leg, and the excitation electrodes on both side surfaces are commonly connected to each other. A metal film for adjusting the frequency is formed at the tip of each leg of the tuning-fork type piezoelectric vibrating piece, and the oscillation frequency is removed by removing the metal film formed on both the main surface and both sides of the tip by beam irradiation. Make adjustments.
Table 2004/100365 gazette

  Incidentally, in recent years, there has been a demand for downsizing of tuning fork type piezoelectric vibrators, and accordingly, downsizing of tuning fork type piezoelectric vibrating pieces provided in the tuning fork type piezoelectric vibrator is also demanded. As a result, with the downsizing of the tuning-fork type piezoelectric vibrating piece, the region for forming the frequency adjusting metal film formed on both the main surface and both side surfaces of the tip portion is also reduced.

  Therefore, regarding the removal of the metal film formed on the side surface of the tip portion, when performing removal by means of metal film removal means such as beam irradiation (laser beam, electron beam, etc.) using the current frequency adjusting device, Although it is necessary to change the design of the apparatus such as changing the angle, the change increases the size of the apparatus, making it difficult to make this change.

  For this reason, it is necessary to perform frequency adjustment using a current frequency adjustment device. In this case, it is difficult to perform beam irradiation on the side surface of the tip portion.

  As described above, the removal of the metal film on the side surface by the beam irradiation is not a realistic frequency adjustment process when a current frequency adjustment apparatus is used.

  In order to solve the above problems, the present invention provides a piezoelectric vibrating device, a tuning fork type piezoelectric vibrating piece, and a tuning fork type piezoelectric vibrating piece that adjust the oscillation frequency without removing the metal film from the side surface of the tip. It aims at providing the manufacturing method of.

  In order to achieve the above object, a tuning fork type piezoelectric vibrating piece frequency adjusting method according to the present invention is a tuning fork type piezoelectric vibrating piece frequency adjusting method for adjusting an oscillation frequency in a wafer on which a plurality of tuning fork type piezoelectric vibrating pieces are formed. The tuning fork type piezoelectric vibrating piece includes a base and a plurality of legs protruding from the base, and a metal film is formed on a side surface of the tip of the leg of the tuning fork type quartz vibrating piece to form a plurality of tuning fork type piezoelectric vibrations. A shift adjustment process for adjusting the oscillation frequency of the wafer on which the piece is formed, a metal film is formed on the main surface of the tip of the leg portion of the tuning-fork type crystal vibrating piece, and the formed metal film is desired by the metal film removing means And a variation adjusting step for adjusting variations in the oscillation frequency of the plurality of tuning fork type piezoelectric vibrating reeds on the wafer.

  According to the present invention, the oscillation frequency can be adjusted without removing the metal film from the side surface of the tip. As a result, even if the tuning fork type piezoelectric resonator element is downsized, the metal film on the side surface is removed by beam irradiation as in the prior art, even if the metal film for frequency adjustment formed on the tip becomes smaller. In addition, it is possible to adjust the shift of the oscillation frequency in the wafer on which a plurality of tuning fork type piezoelectric vibrating pieces are formed and to adjust the variation in the oscillation frequency of the plurality of tuning fork type piezoelectric vibrating pieces on the wafer.

  In the method, the metal film formed in the shift adjusting step has a length in the protruding direction of the leg portion of the metal film forming region formed on the side surface of the tip portion of the tuning fork type piezoelectric vibrating piece at least a part thereof. You may form on the basis of the center of a dimension.

  In this case, of the metal film formed in the shift adjustment step, at least a part of the metal film forming region formed on the side surface of the tip portion of the tuning fork type piezoelectric vibrating piece has a length dimension in the protruding direction of the leg portion. Therefore, it is possible to set a reference for the fluctuation amount of the oscillation frequency, and it is possible to easily shift the oscillation frequency in the wafer on which a plurality of tuning fork type piezoelectric vibrating pieces are formed.

  In the method, at least a part of the metal film formed in the shift adjustment step is a length in the protruding direction of the leg portion of the metal film forming region formed on the side surface of the tip portion of the tuning fork type piezoelectric vibrating piece. You may have length only the same dimension on the front-end | tip part direction side and base part direction side of a leg part along a protrusion direction on the basis of the dimension center.

  In this case, of the metal film formed in the shift adjustment step, at least a part of the metal film forming region formed on the side surface of the tip portion of the tuning fork type piezoelectric vibrating piece has a length dimension in the protruding direction of the leg portion. With the same length as the tip direction side and base direction side of the leg part along the protruding direction with reference to the center of the center, it is possible to set a reference for the fluctuation amount of the oscillation frequency, and a plurality of tuning fork types It is possible to easily shift the oscillation frequency in the wafer on which the piezoelectric vibrating piece is formed. Furthermore, since the length of the leg portion (side surface) in the protruding direction is the same as the length on the distal end side direction and the base direction side of the leg portion along the protruding direction with reference to the center of the length dimension in the protruding direction, the metal on the side surface The amount of film formation and the amount of fluctuation of the oscillation frequency can be proportional to each other, which is suitable for shifting the oscillation frequency in a wafer on which a plurality of tuning fork type piezoelectric vibrating pieces are formed.

  In the method, as for the metal film formed in the variation adjusting step, the metal film may be formed in a central portion in plan view other than the outer peripheral edge in plan view of the main surface.

  In this case, since the metal film is formed in the central portion in plan view other than the outer peripheral edge in plan view of the main surface, the metal film formed in the variation adjusting step can be formed even if there is a misalignment due to the mask during the formation of the metal film. A desired amount of metal film can be formed on the main surface of the leg.

  In order to achieve the above object, a tuning fork type piezoelectric vibrating piece according to the present invention is characterized in that frequency adjustment is performed by the frequency adjusting method for a tuning fork type piezoelectric vibrating piece according to the present invention described above.

  According to the present invention, the oscillation frequency can be adjusted without removing the metal film from the side surface of the tip. As a result, even if the tuning fork type piezoelectric resonator element is downsized, the metal film on the side surface is removed by beam irradiation as in the prior art, even if the metal film for frequency adjustment formed on the tip becomes smaller. In addition, it is possible to adjust the shift of the oscillation frequency in the wafer on which a plurality of tuning fork type piezoelectric vibrating pieces are formed and to adjust the variation in the oscillation frequency of the plurality of tuning fork type piezoelectric vibrating pieces on the wafer. Further, the present invention is suitable for a small tuning fork type piezoelectric vibrating piece.

  In order to achieve the above object, a tuning fork-type piezoelectric vibrating piece according to the present invention is provided with a base and a plurality of legs protruding from the base, and a metal film is provided on the side surface of the tip of the legs. Formed to adjust the oscillation frequency shift in the wafer on which the tuning-fork type piezoelectric vibrating piece is formed, a metal film is formed on the main surface of the tip of the leg portion, and oscillations of the plurality of tuning-fork type piezoelectric vibrating pieces on the wafer are performed. Of the metal film forming region formed on the side surface of the tip portion, at least part of the metal film formed to adjust frequency variation and formed on the side surface of the tip portion of the leg portion is the leg. With the center of the length dimension in the protruding direction of the portion as a reference, the length is the same dimension along the protruding direction on the distal end direction side and the base direction side of the leg portion. The piezoelectric vibrating device according to the present invention is characterized by including the tuning-fork piezoelectric vibrating piece according to the present invention.

  According to the present invention, the oscillation frequency can be adjusted without removing the metal film from the side surface of the tip. Specifically, according to the present invention, the shift of the oscillation frequency is performed in a wafer in which the metal film is formed on the side surface of the tip of the leg to form a plurality of tuning fork-type piezoelectric vibrating pieces, and the leg Since the metal film is formed on the main surface of the tip portion of the wafer to adjust the variation in the oscillation frequency of the plurality of tuning fork type piezoelectric vibrating pieces on the wafer, the tip portion is reduced with downsizing of the tuning fork type piezoelectric vibrating piece. Oscillation in a wafer on which a plurality of tuning-fork-type piezoelectric vibrating pieces are formed without removing the metal film on the side surface by beam irradiation as in the prior art, even if the formation area of the metal film for frequency adjustment formed on It is possible to perform frequency shift adjustment and adjustment of variation in oscillation frequency of a plurality of tuning-fork type piezoelectric vibrating pieces on the wafer. Further, the present invention is suitable for a small tuning fork type piezoelectric vibrating piece.

  Further, according to the present invention, at least a part of the metal film for shift adjustment is projected from the leg portion in the metal film forming region formed on the side surface of the tip portion of the tuning fork type piezoelectric vibrating piece. With reference to the center of the length dimension in the direction, the length of the leg portion is the same as the length in the distal direction direction and the base direction direction along the protruding direction. This makes it possible to easily shift the oscillation frequency in a wafer on which a plurality of tuning fork type piezoelectric vibrating pieces are formed. Furthermore, since the length of the leg portion (side surface) in the projecting direction is based on the center, the length of the leg portion is the same as the length on the distal direction side and the base direction side along the projecting direction. The amount of the metal film formed on the side surface and the fluctuation amount of the oscillation frequency can be proportional to each other, which is suitable for shifting the oscillation frequency in a wafer on which a plurality of tuning fork type piezoelectric vibrating pieces are formed.

  According to the present invention, the oscillation frequency can be adjusted without removing the metal film from the side surface of the tip.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment described below, a case where quartz is used as the piezoelectric material is shown. However, the present invention is not limited to this, and the use of quartz as the piezoelectric material is one preferred embodiment.

-Crystal resonator 1
As shown in FIG. 1, the tuning fork type crystal resonator 1 according to the present embodiment (which is a piezoelectric vibration device according to the present invention, hereinafter referred to as a crystal resonator) is formed by a photolithography method. The quartz crystal vibrating piece 3 (the tuning fork type piezoelectric vibrating piece referred to in the present invention, hereinafter referred to as a quartz vibrating piece), the base 2 holding the quartz vibrating piece 3, and the quartz vibrating piece 3 held on the base 2 are hermetically sealed. And a lid (not shown) for stopping.

  In this crystal unit 1, a base 2 and a lid are joined to form a main body casing. The base 2 and the lid are joined via a joining material (not shown), and the interior space 11 of the main body housing is formed by this joining. The crystal resonator element 3 is held and joined to the base 2 in the internal space 11 of the main body casing via conductive bumps 25 made of a metal material such as gold, and the internal space 11 of the main body casing. Is hermetically sealed. At this time, the base 2 and the crystal vibrating piece 3 are ultrasonically bonded by the FCB method using the conductive bumps 25 and are electrically connected.

  Next, each configuration of the crystal resonator 1 will be described.

  The base 2 is formed in a box-like body composed of a bottom portion 21 and a bank portion 22 extending upward from the bottom portion 21. The base 2 is formed by integrally firing a rectangular parallelepiped of a ceramic material on a single rectangular plate in a plan view made of a ceramic material. Moreover, the bank part 22 is shape | molded along the planar view outer periphery of the bottom part 21 shown in FIG. A metallized layer 23 is provided on the upper surface of the bank portion 22 to be joined to the lid. The metallized layer 23 has, for example, a structure in which nickel and gold are plated in this order on a tungsten layer or a molybdenum layer. Further, as shown in FIG. 1, a pair of electrode pads 24 are formed on the bottom portion 21 in the internal space 11 of the base 2, and the crystal vibrating piece 3 is provided on the electrode pads 24 while being held in one piece. These electrode pads 24 are electrically connected to terminal electrodes (not shown) formed on the outer peripheral surface such as the back surface of the base 2 via corresponding routing electrodes (not shown). Connected to external electrodes of external parts and devices. The electrode pad 24, the lead electrode, and the terminal electrode are formed by printing a metallized material such as tungsten or molybdenum and then firing it integrally with the base 2. And some of these electrode pads 24, routing electrodes, and terminal electrodes are formed by forming nickel plating on the metallized upper portion and forming gold plating on the upper portion thereof.

  The lid is made of a metal material and formed into a single plate having a rectangular shape in plan view. A bonding material is formed on the lower surface of the lid. The lid is electromechanically joined to the base 2 via a joining material by a technique such as seam welding, beam welding, and heat-melt joining, so that a main body housing of the crystal unit 1 is configured by the lid and the base 2. The

  Next, the crystal vibrating piece 3 disposed in the internal space 11 will be described.

-Crystal vibrating piece 3-
The quartz crystal vibrating piece 3 is a quartz crystal Z plate that is formed by wet etching from a quartz base plate (not shown) that is a quartz crystal piece of anisotropic material. Therefore, this crystal vibrating piece 3 is suitable for mass production.

  As shown in FIGS. 1 and 2, the quartz crystal vibrating piece 3 has an outer shape composed of a base portion 31 and two leg portions 32 and 33 that are vibrating portions, and the two leg portions 32 and 33 are formed. It is formed to protrude from one end of the base 31.

  Further, in the outer shape of the crystal vibrating piece 3, both side surfaces 34 face each other, both main surfaces 35 face each other, and these side surfaces 34 are formed so as to be inclined with respect to the main surface 35. This is because the etching speed in the crystal direction (X, Y direction) of the material of the substrate 21 is different when the quartz crystal resonator element 3 is wet-etched.

  In addition, a concave portion 36 is formed on both main surfaces 35 of the two leg portions 32 and 33 in order to improve the series resonance resistance value (CI value in the present embodiment) that deteriorates due to the miniaturization of the crystal vibrating piece 3. Has been.

  The leg portions 32 and 33 are provided with first and second excitation electrodes 41 and 42 having different potentials, and the first and second excitation electrodes 41 and 42 as electrode pads 24 serving as external electrodes. An extraction electrode 43 that is extracted from the first and second excitation electrodes 41 and 42 is provided for electrical connection. Note that the extraction electrode 43 in the present embodiment refers to an electrode pattern extracted from the first and second excitation electrodes 41 and 42.

  The first excitation electrode 41 is formed on both main surfaces 35 of one leg portion 32 and both side surfaces 34 of the other leg portion 33. Similarly, the second excitation electrode 42 is formed on both main surfaces 35 of the other leg portion 33 and both side surfaces 34 of the one leg portion 32. Further, part of the two excitation electrodes 41 and 42 is formed inside the recess 36, respectively. For this reason, even if the crystal vibrating piece 3 is downsized, the vibration loss of the legs 32 and 33 is suppressed, and the CI value can be suppressed low.

  The first and second excitation electrodes 41 and 42 are thin films formed by forming a chromium layer on the legs 32 and 33 by metal vapor deposition, and forming a gold layer on the chromium layer. is there. In the present embodiment, the film thickness of the first and second excitation electrodes 41 and 42 is 5 to 10 nm for the chromium layer and 10 to 500 nm for the gold layer.

  Further, as shown in FIGS. 1 and 2, metal films 5 as frequency adjusting weights are respectively formed at the tip portions 37 of the leg portions 32 and 33. These metal films 5 are connected to the first and second excitation electrodes 41 and 42, respectively. Specifically, a part of the metal film 5 is a thin film 51 in which a chromium layer and a gold layer of the same material as the first and second excitation electrodes 41 and 42 are stacked, and the first and second excitation electrodes 41, At the same time as 42, each leg 32, 33 is formed. Then, on the thin film 51 in which the chromium layer and the gold layer are laminated, the gold plating 52 (a part of the metal film 5 in the present invention) is laminated by electrolytic plating to form the metal film 5.

  Specifically, as shown in FIGS. 1 and 2, the metal film 5 is formed at the distal end portion 37 of each leg portion 32, 33, and the metal film 5 on both side surfaces 34 of the distal end portion 37 includes a plurality of crystal vibrating pieces. 3 is formed to adjust the oscillation frequency shift in the wafer 6 (see below), and the metal film 5 is formed on both main surfaces 35 of the tip 37 so that the oscillation frequencies of the plurality of crystal vibrating pieces 3 in the wafer 6 are adjusted. It is formed to adjust the variation. The dimensions of the formation region A3 of the metal film 5 are set such that the width is about 100 to 120 μm, the height is about 100 μm, and the length is about 450 μm.

  Then, the gold plating 52 of the metal film 5 formed on both main surfaces 35 of the leg portions 32 and 33 is formed on the central portion A1 in plan view other than the outer peripheral edge of the main surfaces 35 except for the portion 521. ing. As shown in FIGS. 1 and 2, by adjusting the frequency by removing the metal film 5 of the crystal vibrating piece 3, the tips of both main surfaces 35 of the legs 32 and 33 are shown in FIGS. The gold plating 52 (see FIG. 4) formed in the vicinity has been removed (see the arrow A2 region shown in FIGS. 1 and 2).

  Further, the gold plating 52 of the metal film 5 of a part 521 formed on both main surfaces 35 of the leg portions 32 and 33 is continuous with the gold plating 52 formed on both side surfaces 34. That is, in the part 521 of the gold plating 52 of the metal film 5, as shown in FIGS. 1 and 2, the gold plating 52 formed on both the main surfaces 35 and the both side surfaces 34 is continuously formed.

  The gold plating 52 of the metal film 5 formed on the both side surfaces 34 of the leg portions 32 and 33 is the center of the length dimension (see the center line C shown in FIGS. 1 and 2) in the metal film 5 formation region A3. As a reference, the legs 32 and 33 have the same length on the tip side (tip side 37 direction side) and the base side (base part 31 direction side) and are formed on the entire side surface 34 in the length. Yes. In the present embodiment, the gold plating 52 includes a center line C, and from the center line C along the protruding direction of the leg portions 32, 33, the distal end side (the distal end portion 37 direction side) and the base of the leg portions 32, 33 are provided. Each side (base 31 direction side) has a length of 150 μm.

  Of the gold plating 52 of the metal film 5 described above, the gold plating 52 of the metal film 5 formed on both side surfaces 34 of the legs 32 and 33 is a wafer 6 on which a plurality of crystal vibrating pieces 3 are formed (see below). In order to shift the oscillation frequency to a target oscillation frequency (shift adjustment of oscillation frequency).

  Further, the gold plating 52 of the metal film 5 formed on both the main surfaces 35 of the leg portions 32 and 33 is for adjusting the variation in the oscillation frequency of the plurality of crystal vibrating pieces 3 formed on the wafer 6 (see below) ( (Oscillation frequency variation adjustment). Note that the above-described process of removing the metal film by beam irradiation according to the prior art corresponds to the variation adjustment of the oscillation frequency.

  Next, the wafer 6 and the frequency adjustment process (method) for forming the plurality of crystal vibrating pieces 3 will be described.

-Wafer 6 and frequency adjustment process-
A plurality of crystal vibrating pieces 3 are formed in a matrix on one crystal wafer 6 (hereinafter referred to as a wafer) by a method such as photolithography as shown in FIG. Specifically, each crystal vibrating piece 3 is formed on the wafer 6 with a base 31 and two legs 32 and 33.

  Before the plurality of crystal vibrating pieces 3 are separated into individual pieces from the wafer 6 having the above-described configuration, each crystal vibrating piece 3 is provided with first and second excitation electrodes 41 and 42 and a metal film 5 (at this time, gold plating). 52 is not formed) and inspection electrodes (not shown) corresponding to the quartz crystal vibrating pieces 3 are formed. The inspection electrode is connected to the first and second excitation electrodes 41 and 42 by a conductive pattern (not shown).

  The first and second excitation electrodes 41 of the crystal vibrating piece 3 to be frequency adjusted from the inspection electrode with respect to the wafer 6 having a structure before the plurality of crystal vibrating pieces 3 are separated from the wafer 6 into individual pieces, A voltage is applied to 42 to excite the crystal vibrating piece 3. Then, the frequency of the quartz crystal vibrating piece 3 is measured while the quartz crystal vibrating piece 3 is excited.

  Then, in order to shift the oscillation frequency in the wafer 6 on which the plurality of crystal vibrating pieces 3 in the state where the gold plating 52 is not formed to the target oscillation frequency to be a target, both sides 34 of each crystal vibrating piece 3 are desired. The amount of gold plating 52 is formed (shift adjustment step). At this time, the gold plating 52 is formed on both main surfaces 35 of the leg portions 32 and 33 at the same time. The quartz crystal vibrating piece 3 on which the gold plating 52 is formed is shown in FIG.

  In the shift adjustment process of the present embodiment described above, the metal film 5 (the gold plating 52 in the present embodiment) is formed on the side surface 34 of the tip portion 37 of the leg portions 32 and 33 of the crystal resonator element 3 to form a plurality of crystal resonator elements. Shift adjustment of the oscillation frequency is performed in the wafer 6 on which 3 is formed. In this shift adjustment process, the gold plating 52 is formed at the center of the length dimension in the protruding direction of the leg portions 32 and 33 in the formation region A3 of the metal film 5 formed on the side surface 34 of the tip portion 37 of the crystal vibrating piece 3 (the center). Formed with reference to line C). Specifically, the gold plating 52 is formed such that the distal end side (the distal end portion) of the leg portions 32 and 33 along the projecting direction with reference to the center (center line C) of the length dimension in the projecting direction of the side surface 34 of the leg portions 32 and 33. 37 side) and the base side (base 31 direction side) have the same length.

  FIG. 5 shows the shift amount of the oscillation frequency with respect to the amount of gold plating formed on the side surface 34 of each crystal vibrating piece 3 in this embodiment. The dimension shown in FIG. 5 is the dimension in the length direction of the gold plating 52 (dimension a value). When the center line C of the formation region A3 of the metal film 5 is used as a reference, the front end side of each leg 32, 33 and The dimensions to the base side are each half of the dimension a value. As shown in FIG. 5, since the dimensions of the leg portions 32 and 33 toward the distal side and the proximal side are set with reference to the center line C of the formation region A3 of the metal film 5, to the side surface 34. The formation amount (dimension a value) of the gold plating 52 and the amount of change in the oscillation frequency are in a proportional relationship.

  Then, as described above, after adjusting the oscillation frequency shift in the wafer 6 on which the plurality of crystal vibrating pieces 3 are formed, the gold plating 52 of the metal film 5 formed on both the main surfaces 35 of the legs 32 and 33 is performed. On the other hand, the gold plating 52 is removed by a metal film removing means using a laser beam or the like using a device that performs a frequency adjusting device (not shown), and the variation in the oscillation frequency of the plurality of crystal vibrating pieces 3 on the wafer 6 is adjusted. (Dispersion adjusting step) The adjustment of the oscillation frequency in the wafer 6 on which the plurality of crystal vibrating pieces 3 are formed is finished. As described above, when adjusting the variation in the oscillation frequency, the metal film is not removed from the metal film 5 formed on the side surfaces 34 of the legs 32 and 33.

  In the shift adjustment process of the present embodiment described above, the gold plating 52 is formed on both main surfaces 35 of the tip portions 37 of the leg portions 32 and 33 of the crystal vibrating piece 3, and the formed metal film 5 is desired by the metal film removing means. The variation of the oscillation frequency of the plurality of crystal vibrating pieces 3 on the wafer 6 is adjusted by removing the amount.

  Specifically, the gold plating 52 of the metal film 5 formed on the main surfaces 35 of the legs 32 and 33 is irradiated with a laser while scanning the width direction of the legs 32 and 33 to the gold plating 52 of the metal film 5. Then, the gold plating 52 is removed in a line shape. The removal target of the metal film 5 here is intended only for the gold plating 52 formed by electrolytic plating. Then, the removal of the line-shaped metal film 5 by the laser irradiation is performed from the distal end portion 37 side (the distal end side) of the leg portions 32 and 33 toward the base portion 31 side (the proximal side). By removing, the shape of the metal film 5 becomes as shown in FIG.

  After finishing the oscillation frequency adjustment in the wafer 6 on which the plurality of crystal vibrating pieces 3 are formed, the plurality of crystal vibrating pieces 3 are divided from the wafer 6 into individual pieces shown in FIG. The crystal unit 1 is manufactured by mounting on the base 2 (see FIG. 1) and bonding the lid to the base 2 in order to hermetically seal the crystal vibrating piece 3.

  As described above, according to the method for adjusting the frequency of the quartz crystal resonator element 3 according to the present embodiment, the shift adjustment step and the variation adjustment step are included. Therefore, the metal film 5 is removed from the side surface 34 of the tip portion 37. Therefore, the oscillation frequency can be adjusted. As a result, even if the formation region of the frequency-adjusting metal film 5 formed on the distal end portion 37 is reduced with the miniaturization of the crystal vibrating piece 3, the metal film 5 on the side surface 34 by the beam irradiation as in the prior art is reduced. Without removal, it is possible to adjust the shift of the oscillation frequency in the wafer 6 on which the plurality of crystal vibrating pieces 3 are formed and to adjust the variation in the oscillation frequency of the plurality of crystal vibrating pieces 3 on the wafer 6.

  Further, of the metal film 5 formed in the shift adjustment step, at least a part of the gold plating 52 is formed in the leg portion 32 in the formation region A3 of the metal film 5 formed on the side surface 34 of the tip portion 37 of the crystal vibrating piece 3. , 33 is formed with reference to the center of the length dimension in the projecting direction (center line C), so that the reference of the fluctuation amount of the oscillation frequency can be determined, and the oscillation frequency in the wafer 6 on which the plurality of crystal vibrating pieces 3 are formed. Can be easily shifted.

  Furthermore, with the center (center line C) of the length dimension in the protruding direction of the legs 32, 33 (side surface 34) as the reference, the same as the distal direction side and the base direction side of the legs 32, 33 along the protruding direction. Since the length is only the size, the amount of formation of the metal film 5 on the side surface 34 and the amount of fluctuation of the oscillation frequency can be proportional to each other, and the oscillation frequency shift in the wafer 6 on which the plurality of crystal vibrating pieces 3 are formed. It is suitable for.

  Further, for the metal film 5 (gold plating 52 in the present embodiment) formed in the variation adjusting step, the gold plating 52 is formed in the central portion in plan view other than the outer peripheral edge in plan view of the main surface 35 (see FIGS. 1 and 2). A desired amount of the gold plating 52 can be formed on the main surfaces 35 of the legs 32 and 33 even if there is a misalignment due to the mask when the gold plating 52 is formed.

  Since the crystal resonator element 3 provided in the crystal resonator 1 according to the above-described embodiment is frequency-adjusted by the frequency adjusting method according to the above-described embodiment, the operational effects of the above-described frequency adjusting method can be obtained. The oscillation frequency can be adjusted without removing the metal film 5 from the side surface 34 of the tip portion 37. As a result, even if the formation region of the frequency-adjusting metal film 5 formed on the distal end portion 37 is reduced with the miniaturization of the crystal vibrating piece 3, the metal film 5 on the side surface 34 by the beam irradiation as in the prior art is reduced. Without removal, it is possible to adjust the shift of the oscillation frequency in the wafer 6 on which the plurality of crystal vibrating pieces 3 are formed and to adjust the variation in the oscillation frequency of the plurality of crystal vibrating pieces 3 on the wafer 6. In particular, the present embodiment is suitable for a small crystal vibrating piece 3.

  Further, the crystal resonator element 3 provided in the crystal resonator 1 according to the above-described embodiment is provided with a base portion 31 and two leg portions 32 and 33, and a side surface of the distal end portion 37 of the leg portions 32 and 33. A metal film 5 (gold plating 52 in this embodiment) is formed on 34 for adjusting the oscillation frequency shift in the wafer 6 on which the plurality of crystal vibrating pieces 3 are formed. A metal film 5 (gold plating 52 in this embodiment) is formed on the surface 35 in order to adjust the variation in the oscillation frequency of the plurality of crystal vibrating pieces 3 on the wafer 6, and the side surface 34 of the tip portion 37 of the legs 32 and 33. The gold plating 52 of the metal film 5 formed on the center of the length dimension in the protruding direction of the legs 32 and 33 in the formation region A3 of the metal film 5 formed on the side surface 34 of the tip 37 (center line C). With reference to the legs 32, 3 along the protruding direction Since it has only the same length dimension of the distal direction side and the proximal side, it is possible to adjust the oscillation frequency without removal of the metal film 5 with respect to the side surface 34 of the tip 37.

  Specifically, according to the crystal vibrating piece 3 provided in the crystal resonator 1 according to the present embodiment, the metal film 5 is formed on the side surface 34 of the distal end portion 37 of the legs 32 and 33 to form a plurality of crystal vibrating pieces. 3 is adjusted, and the metal film 5 is formed on the main surface 35 of the tip 37 of the legs 32 and 33 to vary the oscillation frequency of the plurality of crystal vibrating pieces 3 on the wafer 6. Therefore, even if the formation region of the frequency adjusting metal film 5 formed on the tip portion 37 is reduced with the miniaturization of the quartz crystal vibrating piece 3, the metal film on the side surface 34 by beam irradiation as in the prior art is used. Without removing 5, the shift adjustment of the oscillation frequency in the wafer 6 on which the plurality of crystal vibrating pieces 3 are formed and the variation adjustment of the oscillation frequency of the plurality of crystal vibrating pieces 3 on the wafer 6 can be performed. In particular, the present embodiment is suitable for a small crystal vibrating piece 3.

  Further, according to the crystal vibrating piece 3 provided in the crystal resonator 1 according to the present example, at least the gold plating 52 is formed on the side surface 34 of the tip portion 37 of the crystal vibrating piece 3 for the shift adjusting metal film 5. In the formed region A3 of the metal film 5, with respect to the center of the length dimension in the protruding direction of the leg portions 32 and 33 (center line C), the tip end direction side of the leg portions 32 and 33 along the protruding direction Since the length is the same dimension on the base direction side, it is possible to set a reference for the fluctuation amount of the oscillation frequency, and it is possible to easily shift the oscillation frequency in the wafer 6 on which the plurality of crystal vibrating pieces 3 are formed. Furthermore, with the center (center line C) of the length dimension in the protruding direction of the legs 32, 33 (side surface 34) as the reference, the same as the distal direction side and the base direction side of the legs 32, 33 along the protruding direction. Since the length is only the size, the amount of formation of the metal film 5 on the side surface 34 and the amount of fluctuation of the oscillation frequency can be proportional to each other, and the oscillation frequency shift in the wafer 6 on which the plurality of crystal vibrating pieces 3 are formed. It is suitable for.

  In this embodiment, the laser beam is used for the frequency adjustment method by removing the metal film 5 of the crystal vibrating piece 3. However, the present invention is not limited to this, and other metal film removal means such as ion milling may be used. May be.

  Further, in this embodiment, the gold plating 52 of the metal film 5 is used as a metal film object for shift adjustment and as a metal film object for variation adjustment. However, the present invention is not limited to this. In this embodiment, the thin film 51 made of a chromium layer and a gold layer may also be used as a metal film for shift adjustment and a metal film for variation adjustment. In this case, the thin film 51 made of the chromium layer and the gold layer is not formed over the entire formation region A3 of the metal film 5, and it goes without saying that the formation amount is varied according to the adjustment amount of the oscillation frequency. .

  In the present embodiment, the metal film 5 is simultaneously formed on the side surfaces 34 and both main surfaces 35 of the tip portions 37 of the leg portions 32 and 33 of the crystal vibrating piece 3, but this is a preferred example. It is not limited to this. Therefore, for example, the metal film 5 is formed only on the side surfaces 34 of the tip portions 37 of the leg portions 32 and 33 of the crystal vibrating piece 3 to perform the shift adjustment process. The variation adjustment process may be performed by forming the metal film 5 only on both main surfaces 35 of the tip portions 37 of the leg portions 32 and 33. That is, regarding the formation of the metal film 5, the target metal film 5 may be formed for each step of the shift adjustment step and the variation adjustment step, or the target metal film as shown in this embodiment. 5 may be formed simultaneously.

  Further, in this embodiment, after adjusting the oscillation frequency in the wafer 6 on which the plurality of crystal vibrating pieces 3 are formed, the gold plating 52 of the metal film 5 formed on both main surfaces 35 of the leg portions 32 and 33 is performed. Although the gold plating 52 is removed by the metal film removing means, this is a preferable example, and the removal target of the gold plating 52 is not limited to this. Therefore, for example, the removal target of the gold plating 52 may be any one of the main surfaces 35 of the leg portions 32 and 33.

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

  The present invention relates to frequency adjustment of a tuning fork type piezoelectric vibrating piece, and in particular, a step of performing frequency adjustment on each piezoelectric vibrating piece continuously before separating the plurality of tuning fork type piezoelectric vibrating pieces integrally formed on the wafer from the wafer. Very efficient and suitable. Further, the present invention is suitable particularly when the tuning fork type piezoelectric vibrator is a tuning fork type crystal vibrator.

FIG. 1 is a schematic plan view showing the inside of a crystal resonator according to the present embodiment. FIG. 2 is a schematic perspective view schematically showing a crystal vibrating piece subjected to a shift adjustment step and a variation adjustment step according to the present embodiment. FIG. 3 is a schematic plan view showing a part of the wafer according to the present embodiment. FIG. 4 is a schematic perspective view schematically showing a crystal vibrating piece on which gold plating is formed according to this example. FIG. 5 is a graph showing the shift amount of the oscillation frequency with respect to the amount of gold plating formed on the side surface of the quartz crystal vibrating piece in the present embodiment.

Explanation of symbols

3 Crystal vibrating piece (Tuning Fork type piezoelectric vibrating piece)
31 Base 32, 33 Leg 34 Side 35 Main surface 37 Tip 5 Metal film 52 Gold plating 6 Wafer

Claims (7)

In a tuning fork type piezoelectric vibrating piece frequency adjusting method for adjusting an oscillation frequency in a wafer on which a plurality of tuning fork type piezoelectric vibrating pieces are formed,
The tuning fork-type piezoelectric vibrating piece includes a base and a plurality of legs protruding from the base.
A shift adjustment step for adjusting the oscillation frequency in a wafer in which a plurality of tuning fork type piezoelectric vibrating pieces are formed by forming a metal film on the side surface of the tip of the leg portion of the tuning fork type crystal vibrating piece;
A metal film is formed on the main surface of the tip of the leg portion of the tuning-fork type crystal vibrating piece, and the formed metal film is removed by a desired amount by the metal film removing means to oscillate a plurality of tuning-fork type piezoelectric vibrating pieces on the wafer. A frequency adjusting method for adjusting the frequency variation, and a frequency adjusting method for a tuning-fork type piezoelectric vibrating piece. In the frequency adjustment method of the tuning fork type piezoelectric vibrating piece according to claim 1,
Of the metal film formed in the shift adjustment step, at least a part of the metal film forming region formed on the side surface of the tip portion of the tuning fork type piezoelectric vibrating piece has the center of the length dimension in the protruding direction of the leg portion. A method for adjusting the frequency of a tuning-fork type piezoelectric vibrating piece, characterized by being formed as a reference. In the frequency adjustment method of the tuning fork type piezoelectric vibrating piece according to claim 1,
About the metal film formed in the shift adjustment step, at least a part of the metal film forming region formed on the side surface of the tip of the tuning fork type piezoelectric vibrating piece has the center of the length dimension in the protruding direction of the leg part. A frequency adjustment method for a tuning-fork type piezoelectric vibrating piece, characterized by having a length of the same dimension on a distal end side direction side and a base direction side of a leg portion along a protruding direction as a reference. In the frequency adjustment method of the tuning fork type piezoelectric vibrating piece according to any one of claims 1 to 3,
A frequency adjustment method for a tuning-fork type piezoelectric vibrating piece, wherein the metal film formed in the variation adjusting step is formed in a central portion in plan view other than the outer peripheral edge in plan view of the main surface.   A tuning-fork type piezoelectric vibrating piece, wherein frequency adjustment is performed by the frequency adjustment method according to claim 1. In tuning fork type piezoelectric vibrating piece,
A base and a plurality of legs projecting from the base;
A metal film is formed on the side surface of the tip of the leg portion in order to perform shift adjustment of the oscillation frequency in the wafer on which a plurality of the tuning fork type piezoelectric vibrating pieces are formed,
A metal film is formed on the main surface of the tip portion of the leg portion in order to adjust variation in oscillation frequency of the plurality of tuning-fork type piezoelectric vibrating pieces on the wafer,
At least a part of the metal film formed on the side surface of the distal end portion of the leg portion has a center of the length dimension in the protruding direction of the leg portion in the formation region of the metal film formed on the side surface of the distal end portion. A tuning fork-type piezoelectric vibrating piece having the same length as the reference on the distal direction side and the base direction side of the leg along the protruding direction.   A piezoelectric vibrating device comprising the tuning-fork type piezoelectric vibrating piece according to claim 5 or 6.

Images