JP3997526B2 - Quartz crystal resonator element, processing method thereof, crystal device, mobile phone device using crystal device, and electronic device using crystal device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a crystal vibrating piece and a processing method thereof, a crystal device using the crystal vibrating piece, a manufacturing method thereof, and a mobile phone and an electronic apparatus using the crystal device.
[0002]
[Prior art]
Quartz that contains a crystal resonator element in a small information device such as a hard disk drive (HDD), mobile computer, or IC card, or mobile communication device such as a mobile phone, a car phone, or a paging system Crystal devices such as vibrators and crystal oscillators are widely used.
FIG. 8 is a schematic cross-sectional view showing a configuration example of such a crystal device (see Patent Document 1).
In the figure, a quartz crystal device 1 accommodates a quartz crystal vibrating piece 3 inside a package 2. In this case, the package 2 is formed by forming an insulating material in a shallow box shape. After the quartz crystal vibrating piece 3 is accommodated and fixed inside, the package 2 is sealed by a transparent lid 4 such as glass.
[0003]
The package 2 is formed by forming, laminating and sintering a plurality of substrates 2a and 2b made of ceramic green sheets. Inside the substrate 2b, holes are formed by removing the material at the time of forming. By providing this, a space S1 for accommodating the crystal vibrating piece 3 is formed as shown in the figure.
[0004]
The quartz crystal resonator element 3 is, for example, a so-called tuning fork type resonator element including a pair of vibrating arms having one end as a base by etching the crystal and extending in parallel to the one from the base, or a so-called AT-cut resonator piece obtained by cutting a crystal into a rectangle. The driving excitation electrode 6 is formed on the front and back surfaces thereof.
The quartz crystal vibrating piece 3 is supported in a cantilever manner by joining the base 3a at the internal space S1 of the package 2 to the package side.
[0005]
Specifically, an electrode unit 5 connected to a mounting electrode unit (not shown) provided on the bottom surface of the package is formed on the surface of the substrate 2a using the substrate 2a of the package 2 as a base. A lead electrode 6 a connected to the excitation electrode 6 provided on the base 3 a of the crystal vibrating piece 3 is joined.
The electrode part 5 is formed by plating nickel and gold on a tungsten metallization, for example. The conductive adhesive 7 is applied to the surface of the electrode part 5, the base 3a of the crystal vibrating piece 3 is placed thereon, and the conductive adhesive 7 is cured, whereby the crystal vibrating piece 3 is joined.
[0006]
[Patent Document 1]
JP 2000-85963 A
[0007]
[Problems to be solved by the invention]
The quartz crystal vibrating piece 3 used in such a quartz crystal device 1 forms the quartz crystal vibrating piece 3 itself from quartz as a piezoelectric material, and further accommodates the quartz crystal vibrating piece 3 in the package 2 to form the quartz crystal device 1. In the process, various processes related to vibration performance are performed.
For example, when the crystal vibrating piece 3 is joined using the conductive adhesive 7 or the like as shown in FIG. 8, the vibration of the crystal vibrating piece 3 leaks to the package 2 side through the joining portion. In order to limit the vibration region of the resonator element 3 in advance, there is a method in which the vicinity of the joint portion is polished to form a so-called convex type crystal resonator element.
[0008]
The excitation electrode 6 of the crystal vibrating piece 3 is formed by vapor deposition or sputtering. By increasing the thickness of this electrode, the frequency is adjusted to increase the mass and lower the vibration frequency of the crystal vibrating piece 3. The
Alternatively, after the crystal vibrating piece 3 is formed, it is bonded to the package 2 as shown in FIG. 8 and after the lid 4 is sealed, the laser beam LB is transmitted from the outside so as to transmit the transparent lid 4. A part of the excitation electrode 6 of the crystal vibrating piece 3 is irradiated to evaporate a part of the electrode material, and the frequency is adjusted by increasing the vibration frequency of the crystal vibrating piece 3 by a mass reduction method.
[0009]
Further, when the lid 4 is made of a metal material, the lid 4 is irradiated with the laser beam LB from the outside as in FIG. 8, but in this case, the lid 4 does not transmit the laser beam LB. Therefore, the laser beam LB heats the irradiated portion of the lid 4, attaches the vaporized metal component to the surface of the crystal vibrating piece 3, and adjusts the frequency so as to increase the vibration frequency of the crystal vibrating piece 3. Sometimes it is done.
[0010]
In such various conventional processing methods, for example, when the quartz crystal resonator element 3 is processed to limit the vibration region as described above, a special type of polishing is used to form a convex crystal resonator element. It is necessary to provide a process, and the work is complicated and requires a long time.
In the frequency adjustment processing described above, the frequency cannot be adjusted when the excitation electrode 6 is provided, after the excitation electrode 6 is provided, or unless a metal film dedicated to frequency adjustment is provided separately from the electrode.
In particular, in the frequency adjustment of the mass reduction method, it is necessary to form an extra electrode or a metal film dedicated to frequency adjustment corresponding to the frequency adjustment, resulting in waste of materials.
[0011]
Furthermore, the method of adjusting the frequency of the mass reduction method as shown in FIG. 8 is relatively easy when the quartz crystal vibrating piece 3 is a tuning fork type vibrating piece, but when it is an AT cut vibrating piece. There is a high possibility that the quality is deteriorated due to the thermal influence of the laser beam LB. For this reason, the frequency adjustment of the quartz crystal resonator element 3 using the AT-cut resonator element is practically performed by adjusting the film thickness when forming the electrode film before sealing the package 2 with the cover body 4. It is.
When the lid 4 is hermetically sealed after adjusting the frequency of the quartz crystal resonator element 3, the condition of the internal space S1 changes, which causes a problem that the vibration frequency changes.
As described above, the conventional method needs to adopt different processing methods for the case where the vibration region of the crystal vibrating piece 3 is limited and the case where the frequency adjustment is performed. The degree of freedom in designing is limited. In addition, depending on the type of crystal resonator element, there are various problems such as a common frequency adjustment method cannot be employed.
[0012]
The present invention has been made to solve the above-described problems, and can be used in common regardless of the type of crystal resonator element when the vibration region of the crystal resonator element is limited or the frequency is adjusted. An object of the present invention is to provide a method for processing a quartz crystal resonator element, a crystal resonator element and a crystal device formed by the processing method, a manufacturing method thereof, and a mobile phone and an electronic apparatus using the crystal device.
[0013]
[Means for Solving the Problems]
The above object is achieved according to the first invention. By concentrating the laser light inside the end portion of the thickness-shear vibration type crystal resonator element, a portion where the crystal structure is changed or broken is created inside the crystal resonator element. The vibration region is limited to the inside of the part This is achieved by the processing method of the crystal vibrating piece.
According to the configuration of the first invention, the inside of the quartz crystal vibrating piece is irradiated with the laser light. (Focusing) Thus, the crystal structure of the irradiated part is changed or the crystal structure is destroyed. Thereby, since the crystal structure becomes discontinuous in the region, the vibration region of the quartz crystal vibrating piece is limited to a divided region such as an inner side of the laser light irradiation site. For this reason, since a special polishing process and a long polishing time are not required as compared with conventional convex processing, processing is extremely easy and processing time can be shortened.
In addition, frequency adjustment that does not assume the presence of an electrode or a metal film can be performed by a method similar to the processing for limiting the vibration region of the quartz crystal resonator element. In other words, by irradiating the inside of the quartz crystal vibrating piece with laser light and changing the crystal structure of the irradiated portion or destroying the crystal structure, the vibration region becomes narrow and the vibration frequency becomes high. For this reason, frequency adjustment can be performed by a common method regardless of before and after the electrode film forming step and regardless of the type of the crystal vibrating piece.
[0015]
The second invention is the configuration of the first invention, A femtosecond pulse laser is used as the laser light.
According to the configuration of the second invention, By using a femtosecond pulse laser as the laser light that irradiates the inside of the quartz crystal vibrating piece, the crystal structure only at the target location can be changed, especially in the case of a quartz crystal vibrating piece with a precise structure. It is possible to prevent thermal influences on the periphery other than the location, and it is possible to perform precise processing on all types of crystal vibrating pieces.
[0017]
The above-mentioned purpose is According to the third invention, In the package Thickness sliding vibration type A method of manufacturing a quartz crystal device containing a quartz crystal vibrating piece, a joining step for joining the quartz crystal vibrating piece in the package, and a lid sealing step for sealing the package with a lid after the joining step And at least after the joining step, By focusing the laser beam inside the portion inside the end portion of the quartz crystal vibrating piece, a portion where the crystal structure is changed or destroyed inside the quartz crystal vibrating piece is created, and the vibration region of the quartz crystal vibrating piece is , Limited to the inside of the part This is achieved by a method of manufacturing a quartz crystal device including a process.
According to the configuration of the third invention, In the manufacturing process of crystal devices, after the crystal vibrating piece is joined, the laser beam is irradiated to the inside of the crystal vibrating piece. (Focusing) If the process of changing the crystal structure of the formed portion is performed, frequency adjustment that does not assume the presence of an electrode or a metal film can be performed. In other words, the laser beam is irradiated inside the crystal vibrating piece, and the crystal structure of the irradiated portion is changed or the crystal structure is destroyed. Regardless of the type, frequency adjustment can be performed at any stage required by the same method.
[0018]
A fourth invention is the configuration of the third invention, wherein The lid made of a material that transmits light is used, and after the lid sealing step, the lid is transmitted to irradiate the inside of the crystal vibrating piece in the package with the laser light. It is characterized by that.
According to the configuration of the fourth invention, Precise adjustment of the vibration frequency can be performed immediately before the completion of the quartz device. In this case, since the method is different from the method of evaporating the electrode on the surface of the crystal vibrating piece, the formed electrode is not wasted.
[0019]
Moreover, the above-mentioned object is according to the fifth invention. This is a thickness-shear vibration type quartz crystal vibrating piece, in which a laser beam is focused inside to create a part where the crystal structure has been changed or destroyed inside, and the vibration region is located inside the part. This is achieved by means of a limited crystal resonator element.
According to the configuration of the fifth invention, Compared with the conventional convex type crystal vibrating piece, since the end of the crystal vibrating piece is not polished, the thickness of the end does not change and the flat shape is maintained. In joining, horizontal holding is surely and easily performed with respect to the holding posture of the crystal vibrating piece.
[0020]
Furthermore, the above object is achieved according to the sixth invention in a package or case. Thickness sliding vibration type A quartz crystal device containing a quartz crystal vibrating piece, comprising: A portion where the crystal structure is changed or destroyed is created by focusing the laser beam inside, and the vibration region is located inside the portion. Limited
Achieved by a quartz device.
According to the configuration of the sixth invention, Compared with the conventional convex-type quartz crystal resonator element, the crystal resonator element housed in the package or case is not polished, so the thickness of the end part does not change and the shape is flat. Therefore, the horizontal holding in the joining using an adhesive or the like is reliable. For this reason, when the quartz crystal vibrating piece in the conventional structure is housed in the package in a cantilever manner, the tip is not inclined and the tip portion does not approach the inner surface of the package or the like. Therefore, when the impact is received from the outside and the tip is slightly displaced, the tip does not collide with the inner surface of the package or the like and is damaged, and the reliability is improved. Further, in such a case, it is not necessary to form a recess for avoiding a collision on the inner surface of the package, etc., and accordingly, the thickness of the package or the like can be reduced, and the structure is advantageous for reducing the height or size. Become.
[0021]
The above-mentioned purpose is According to the seventh invention, In package or case Thickness sliding vibration type A mobile phone device using a crystal device containing a crystal resonator element, wherein the crystal resonator element A portion where the crystal structure is changed or destroyed is created by focusing the laser beam inside, and the vibration region is located inside the portion. This is achieved by a portable telephone device that obtains a clock signal for control by a limited crystal device.
[0022]
The above-mentioned purpose is According to the eighth invention, In package or case Thickness sliding vibration type An electronic apparatus using a quartz crystal device containing a quartz crystal vibrating piece, wherein the quartz crystal vibrating piece A portion where the crystal structure is changed or destroyed is created by focusing the laser beam inside, and the vibration region is located inside the portion. This is achieved by an electronic device adapted to obtain a clock signal for control by a limited crystal device.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
1 and 2 show a first embodiment of a quartz crystal device according to the present invention. FIG. 1 is a schematic plan view thereof, and FIG. 2 is a schematic sectional view taken along line AA of FIG.
In the drawing, the crystal device 30 shows an example in which a crystal resonator is configured, and the crystal device 30 houses a crystal vibrating piece 32 in a package 36. The package 36 is formed, for example, by laminating a plurality of substrates formed by molding an aluminum oxide ceramic green sheet as an insulating material, and then sintering.
[0024]
That is, in this embodiment, the package 36 is formed by laminating the first substrate 61, the second substrate 62, and the third substrate 63, and the material inside the third substrate 63 is removed. Thus, a space of the internal space S2 is formed. This internal space S2 is a housing space for housing the crystal vibrating piece.
Here, in the present embodiment, the box-shaped package 36 is formed so as to accommodate the crystal vibrating piece 32. For example, the crystal vibrating piece 32 is bonded to the first substrate 61 that is a base, As a configuration in which a thin box-shaped lid or lid is covered and sealed, the flat first substrate 61 and the lid may constitute a package.
Furthermore, the crystal resonator element 32 may be housed in a metal cylindrical case (not shown) to form a cylinder type crystal device.
[0025]
In the inner space S2 of the package 36, in the vicinity of the left end portion, the second substrate 62 that is exposed to the inner space S2 and constitutes the inner bottom portion has, for example, an electrode portion formed by nickel plating and gold plating on tungsten metallization. 31 and 31 are provided.
The electrode portions 31 are connected to the outside to supply a driving voltage. Specifically, for example, a mounting electrode part (not shown) is formed on the bottom surface of the first substrate 61, and the mounting electrode part and the electrode parts 31, 31 are bonded to a metal paste before firing the first substrate 61. It can be connected by a conductive through-hole formed using tungsten metallization obtained by coating.
[0026]
Conductive adhesives 43, 43 are applied on the electrode parts 31, 31, and the drawers provided on the conductive adhesives 43, 43 at both ends in the width direction of the one end 32 a of the crystal vibrating piece 32. The electrodes 33 and 33 are placed, and the conductive adhesives 43 and 43 are cured. The extraction electrodes 33 and 33 are formed on the front and back surfaces of the quartz crystal vibrating piece 32.
[0027]
The quartz crystal vibrating piece 32 is formed of quartz that is a piezoelectric material that transmits light. In addition to quartz, the piezoelectric vibrating piece may be formed using a transparent piezoelectric material such as lithium niobate. .
In the case of the present embodiment, the crystal vibrating piece 32 cuts the crystal material into a rectangular shape with a thin plate thickness to form a crystal blank (not shown) as a crystal element piece before forming the electrode. It is a so-called AT-cut vibrating piece in which electrodes necessary for the blank are formed.
[0028]
The extraction electrodes 33 and 33 provided on the crystal vibrating piece 32 are connected to excitation electrodes 34 and 34 formed on the front and back of the main surface of the crystal vibrating piece 32. The front and back excitation electrodes 34 and 34 are separated from each other and function as different polarities. As a result, the drive voltage is transmitted from the outside of the package 36 to the extraction electrodes 33 and 33 via the electrode portions 31 and 31, and the drive voltage is applied to the excitation electrodes 34 and 34 from the extraction electrodes 33 and 33. As a result, the quartz crystal vibrating piece 32 generates an electric field in the inside thereof to generate a thickness shear vibration at a predetermined frequency.
The crystal vibrating piece 32 or the crystal blank before electrode formation is processed in the processing direction as described later.
[0029]
A lid 39 is joined to the opened upper end of the package 36 to be hermetically sealed.
When the lid 39 is made of metal, for example, the lid 39 such as Kovar is joined by seam welding or the like using a seam ring 35 such as silver brazing.
The lid 39 can also be formed of a material that transmits light. In this case, after the lid 39 is sealed and fixed to the package 36, as will be described later, the laser beam LB-F is irradiated from the outside to the inside of the tip portion of the crystal vibrating piece 32, and the crystal structure of the irradiation region The frequency is adjusted by changing or destroying. For this purpose, the lid 39 is formed of a material that transmits light, in particular, thin glass.
As a glass material suitable for the lid 39, for example, borosilicate glass is used, for example, as a thin glass manufactured by the downdraw method.
[0030]
In this embodiment, the package 36 is provided with a through hole 37 that communicates the internal space S2 with the outside. This through hole 37 is a form in which the two through holes 37a and the through hole 37b communicate with each other, and the outer first hole 37a is formed to have a larger inner diameter than the second hole 37b opened to the inner space S2 side. An outward stepped portion 37c is formed between the first hole 37a and the second hole 37b. The through-hole 37 is filled with a sealing material 38 as described later, so that the hole is sealed.
[0031]
(Quartz device manufacturing method)
FIG. 3 is a flowchart showing an example of a manufacturing process of the crystal device 30 of FIG.
Of the manufacturing method of the crystal device 30, the crystal vibrating piece 32 has a configuration as described above by etching a crystal wafer to form a crystal blank and forming electrodes necessary for the crystal blank. In this case, a processing method as described later can be applied even at the stage of the crystal blank or after the electrodes are formed.
[0032]
The package 36 forms a first substrate 61 and a second substrate 62 in a plate shape using, for example, a so-called green sheet obtained by kneading a ceramic powder and a binder in a solution and forming it into a sheet shape. Then, the through hole 37 is provided by forming the first hole 37a and the second hole 37b described in FIG. A third substrate 63 from which a part of the inner material has been removed is stacked thereon to form the electrode part 31.
The electrode unit 31 is formed by, for example, applying a tungsten paste on the second substrate 62 before firing and firing it to form tungsten metallized, and then sequentially applying nickel plating and gold plating on the tungsten metallized. It is formed.
The lid 39 may be formed of a metal material using Kovar or the like, or may be formed of a transparent material, both of which are not different from the conventional manufacturing method.
[0033]
Then, as shown by ST11 in FIG. 3, electrodes, that is, extraction electrodes 33 and 33 and excitation electrodes 34 and 34 are formed on the above-described quartz crystal blank.
Processing described later is performed before or after the electrode formation.
[0034]
(Joining process)
Next, as described with reference to FIGS. 1 and 2, for example, conductive adhesives 43 and 43 as bonding means are applied on the electrode portions 31 and 31 of the package 36. Then, the one end portion 32a of the crystal vibrating piece 32 is placed on the applied conductive adhesives 43, 43, and after applying a load from above, the conductive adhesives 43, 43 are cured (ST12). Thereby, the crystal vibrating piece 32 is joined.
For example, the frequency adjustment is performed on the bonded crystal vibrating piece 32 by a processing method described later (ST13). This frequency adjustment is a rough adjustment before sealing.
[0035]
(Sealing process)
Next, the lid body 39 is placed on the package 36 and bonded thereto to perform lid sealing (ST14).
For example, in a vacuum atmosphere, a brazing material 35 such as low melting glass is applied to the upper end of the package 36 and the lid body 39 is fixed, whereby the package 36 is sealed with the lid body 39 (lid sealing). Stop).
After sealing the lid, the package 36 with the lid 39 bonded thereto is heated in a vacuum atmosphere as necessary. For example, a component of gas generated by heating from the conductive adhesive 43 or the like is changed into the internal space. From S2, it discharges outside through the through-hole 37 demonstrated in FIG. 2 (ST15).
Next, a metal sealing material having a spherical shape or the like is placed on the stepped portion 37c of the through hole 37, and the metal 38 melted by irradiating a laser beam or the like from the outside is filled into the through hole 37 (ST16).
[0036]
(Frequency adjustment process)
Further, as shown in FIG. 4, the laser beam LB-F is irradiated from the outside to the tip portion where the excitation electrode 34 of the crystal vibrating piece 32 is not provided via the light-transmitting lid 39. Adjustment is made to increase the vibration frequency of the crystal vibrating piece 32 by focusing and changing the internal crystal structure (ST17) (fine adjustment).
Next, the crystal device 30 is completed through necessary inspections.
[0037]
Here, an embodiment of a processing method of the crystal vibrating piece 32 that can be suitably used in the above manufacturing process will be described.
FIG. 4 shows a laser processing apparatus 50 using the laser beam used in the present embodiment.
The laser beam used in the processing method of the present embodiment has thermal energy that can change, that is, destroy or modify the crystal structure of the crystal vibrating piece (including a “crystal blank”, hereinafter the same) 32. thing. The thermal influence on the area surrounding the area to be changed can be reduced as much as possible. For example, it can be efficiently focused on the region to be changed inside the crystal vibrating piece 32. For this reason, for example, a carbon dioxide laser may be used, a light beam of a high-power YAG laser may be split into beams, or harmonics of the YAG laser may be devised for use.
[0038]
In order to adapt the pulse laser to such a purpose, it is preferable that the laser beam used has a short wavelength or ultrashort wavelength pulse and has a high peak energy. The type of laser to be used is not limited as long as it fits such purpose or is processed so as to fit such purpose. Particularly suitable for such purposes are femto (1/1000 trillion) second (fs) pulsed lasers.
The processing device 50 generates such femtosecond pulsed laser light, and includes two types of laser light generation means Y and TS, synchronous amplification means 54 for the laser light generated by these, and the inside of the crystal vibrating piece 32. And a focusing means 55 for focusing the laser beam.
[0039]
The laser beam generation means TS of the processing apparatus 50 is a titanium sapphire laser or a combination of a titanium sapphire laser and other laser generation means. Titanium sapphire lasers are widely used in generating femtosecond pulse lasers because they emit light with a very broad emission spectrum. The laser beam generating means Y is, for example, a YAG laser.
The synchronous amplification means 54 includes a laser pulse extension means 51, a laser pulse amplification means 52, and a laser pulse compression means 53. The focusing means 55 is a light focusing means, and an objective lens, a hologram element having a light focusing function, or the like is used, and the laser light can be focused within a predetermined range by being moved in the arrow direction.
[0040]
The laser pulse SL from the laser beam generation means TS of the processing apparatus 50 is incident on the laser pulse extension means 51. The laser pulse extension means 51 is formed by pairing a predetermined optical element, for example, a grating (diffraction grating). The laser pulse SL is extended by frequency chirping to widen the pulse width. The laser pulse SL-1 having a wide pulse width enters the laser pulse amplification means 52. The laser pulse YL from the laser light generating means Y is incident on the laser pulse amplifying means 52, and mode locking (synchronization) is performed using this, and the peak power is about 10 GW or so, for example. The amplified laser pulse AL is made incident on the laser pulse compression means 53. The laser pulse compression means 53 is formed with a pair of gratings, for example, and compresses the pulse width of the laser pulse AL while maintaining a high peak power, for example, an ultrashort wavelength of about 100 to 200 fs, for example. The laser pulse CL is made incident on the objective lens 55 which is a focusing means. The laser beam LB-F that has been focused by the objective lens 55 is imaged in the vicinity of the tip of the crystal vibrating piece 32 where the electrode is not formed.
[0041]
FIG. 5 is a diagram for explaining a state of processing by the laser beam LB-F irradiated as described above using the processing apparatus 50.
FIG. 5A is a schematic perspective view of the crystal vibrating piece 32 before processing, and the excitation electrode 34 and the extraction electrodes 33, 33 are formed. Also in the crystal blank before forming these electrodes, This processing method can be applied, and the effect is the same.
[0042]
FIG. 5B is a plan view of the quartz crystal vibrating piece 32 of FIG. 5A, and the vibration area A1 is partitioned by a chain line. As shown in the figure, no processing is performed. Then, the region involved in the vibration extends over the entire length of the crystal vibrating piece 32.
On the other hand, FIG. 5C shows a state in which the crystal vibrating piece 32 is irradiated with the laser beam LB-F, and the irradiation point P1 of the laser beam LB-F is not the surface of the crystal vibrating piece 32. , Inside it. Thereby, as shown in FIG.5 (d), a vibration area | region will be restrict | limited to the area | region of A2. For this reason, as will be described later, the vibration frequency of the crystal vibrating piece 32 is adjusted so as to change high. Here, when the laser beam is focused on the surface of the crystal vibrating piece 32 as in the conventional method, the material on the surface is evaporated, and part of the material may be scattered and adhere to the crystal vibrating piece 32. There are adverse effects such as deteriorating vibration performance.
[0043]
Alternatively, as in other conventional examples, when a laser beam is irradiated on a metal coating portion such as an electrode portion on the surface of the quartz crystal vibrating piece 32, not only a part of the laser beam is evaporated but also the above-mentioned inconvenience occurs. Further, when the heat of the laser light is transmitted to the periphery of the irradiated portion, the material surface portion of the quartz crystal resonator element that is greatly involved in the vibration performance is seriously affected, and the vibration performance of the quartz crystal resonator element 32 is likely to be impaired.
On the other hand, in the present embodiment, the laser beam LB-F is focused inside the crystal vibrating piece 32 so that the surface of the crystal vibrating piece 32 that is greatly involved in the vibration performance is hardly damaged. By using an ultra-short wavelength laser, such as a femtosecond pulsed laser, there is little need to consider the thermal effects on the surroundings.
[0044]
FIG. 6 is a diagram for explaining the frequency change before and after the processing of the crystal vibrating piece 32. FIG. 6A is a plan view of the crystal vibrating piece 32-1 before processing, and the vibration region is almost the same. It shows how it exists over the entire length. FIG. 6B is a graph schematically showing the distribution and frequency of the vibration region corresponding to the length direction of the crystal vibrating piece 32-1 before processing. As shown in FIG. 6B, when the vibration region is large in the length direction, the vibration frequency is relatively low.
On the other hand, in FIG. 6C, both ends P2 and P3 of the crystal vibrating piece are irradiated with the laser beam LB-F, and the crystal vibrating piece 32-2 after the processing is viewed in a plan view. It shows a state limited to the area partitioned inside the parts P2 and P3. FIG. 6D is a graph schematically showing the distribution and frequency of the vibration region corresponding to the length direction of the crystal vibrating piece 32-2 after processing. As shown in FIG. 6D, when the vibration region is limited to the region inside the both ends, the vibration frequency becomes high.
[0045]
As described above, according to the above-described embodiment, the laser beam is irradiated to the inside of the crystal vibrating piece 32, and the crystal structure of the irradiated portion is changed, or the crystal structure is destroyed or modified. For this reason, it is possible to perform frequency adjustment on the crystal vibrating piece 32 without assuming the presence of the excitation electrode 34 or the metal film. In other words, by irradiating the inside of the quartz crystal vibrating piece 32 with laser light and changing the crystal structure of the irradiated portion, or destroying or modifying the crystal structure, the vibration region becomes a narrow range. Get higher.
Therefore, if the frequency adjustment is to increase the vibration frequency, the frequency can be easily adjusted by the same processing method at any stage of ST13 and ST17 in FIG. 3 even in the state of the crystal blank before the crystal vibrating piece is formed. Adjustments can be made.
[0046]
In addition, for example, as shown in FIG. 6 (d), the processing for limiting the vibration region to the region inside the end portion of the quartz crystal vibrating piece 32 is facilitated. Without requiring a long polishing time, it is possible to form a quartz crystal vibrating piece having a limited vibration region as in the convex type, which is extremely easy to process and can shorten the processing time.
[0047]
Furthermore, the crystal vibrating piece 32 formed in this manner is not polished because the end of the crystal vibrating piece 32 is not polished as compared with the conventional convex-type quartz vibrating piece. Since the flat shape is maintained, the horizontal holding in the joining using an adhesive or the like is sure. For this reason, when the quartz crystal vibrating piece is housed in the package in a cantilever manner as seen in the prior art, the tip portion approaches the inner surface of the package or the like, as in the case where the inclined bonding is made. There is no. Therefore, when the impact is received from the outside and the tip is slightly displaced, the tip does not collide with the inner surface of the package or the like and is damaged, and the reliability is improved. Further, in such a case, it is not necessary to form a recess for avoiding a collision on the inner surface of the package, etc., and accordingly, the thickness of the package or the like can be reduced, and the structure is advantageous for reducing the height or size. Become.
In addition, when the crystal vibrating piece 32 or the crystal blank was processed by the above-described processing apparatus 50, the state in which the crystal was broken or changed was often visually recognized as being whiter than the surroundings. Moreover, the change in the crystal structure by the processing method of the present embodiment can be easily found by X-ray analysis.
[0048]
FIG. 7 is a diagram showing a schematic configuration of a digital mobile phone device as an example of an electronic apparatus using the crystal device according to the above-described embodiment of the present invention.
In the figure, a microphone 308 for receiving the voice of the sender and a speaker 309 for outputting the received content as a voice output are provided, and further, an integrated circuit or the like as a control unit connected to the modulation and demodulation unit of the transmission / reception signal CPU (Central Processing Unit) 301 is provided.
In addition to modulation and demodulation of transmission / reception signals, the CPU 301 controls an information input / output unit 302 including an LCD as an image display unit, an operation key for inputting information, and an information storage unit 303 including a RAM and a ROM. To do. For this reason, the crystal device 30 is attached to the CPU 301, and its output frequency is used as a clock signal suitable for the control contents by a predetermined frequency dividing circuit (not shown) incorporated in the CPU 301. ing. The crystal device 30 attached to the CPU 301 may not be a single crystal device 30 but may be an oscillator that combines the crystal device 30 and a predetermined frequency dividing circuit.
[0049]
The CPU 301 is further connected to a temperature compensated crystal oscillator (TCXO) 305, and the temperature compensated crystal oscillator 305 is connected to the transmitter 307 and the receiver 306. Thus, even if the basic clock from the CPU 301 fluctuates when the environmental temperature changes, it is corrected by the temperature compensated crystal oscillator 305 and supplied to the transmission unit 307 and the reception unit 306.
[0050]
As described above, by utilizing the crystal resonator element 32 according to the above-described embodiment and the crystal device 30 having the crystal oscillator piece 32 in an electronic apparatus such as the digital cellular phone device 300 including the control unit, Since the frequency can be adjusted easily and precisely, an accurate clock signal can be generated.
[0051]
The present invention is not limited to the above-described embodiment. Each configuration of each embodiment can be appropriately combined or omitted, and can be combined with other configurations not shown.
In addition, the present invention is not limited to names of gyroscopes (sensors), crystal resonators, crystal oscillators, etc., as long as the crystal resonator element is accommodated inside a case, package, or lid. It can be applied to all crystal devices.
Further, the present invention can be applied not only to the above-described AT-cut vibrating piece but also to a so-called tuning fork type quartz vibrating piece.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing an embodiment of a quartz crystal device of the present invention.
FIG. 2 is a schematic cross-sectional view taken along line AA in FIG.
FIG. 3 is a flowchart corresponding to an example of a manufacturing process of the quartz crystal device according to the embodiment of the present invention.
FIG. 4 is a schematic configuration diagram of a processing apparatus used in a processing method according to an embodiment of the present invention.
5 is a view for explaining a state of processing with laser light irradiated using the processing apparatus of FIG. 4; FIG.
FIG. 6 is a diagram for explaining a frequency change before and after the processing of the crystal vibrating piece according to the embodiment of the present invention.
FIG. 7 is a diagram showing a schematic configuration of a digital cellular phone device as an example of an electronic apparatus using a crystal device according to an embodiment of the present invention.
FIG. 8 is a schematic cross-sectional view showing an example of a conventional crystal device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 30 ... Quartz device, 32 ... Quartz vibrating piece, 33, 33 ... Extraction electrode, 34 ... Excitation electrode, 50 ... Processing apparatus, 54 ... Synchronous amplification means.

Claims (8)

By focusing the laser beam inside the location inside the end of the thickness-shear vibration type crystal vibrating piece, create a site where the crystal structure is changed or destroyed inside the crystal vibrating piece,
The vibration area of the quartz crystal resonator element is limited to the inside of the part.
A method for processing a quartz crystal vibrating piece. The method for processing a crystal vibrating piece according to claim 1, wherein a femtosecond pulse laser is used as the laser light. A method of manufacturing a crystal device in which a thickness-shear vibration type crystal resonator element is housed in a package,
A bonding step of bonding the crystal vibrating piece into the package;
A lid sealing step of sealing the package with a lid after the joining step;
At least after the joining step,
By focusing the laser beam inside the portion inside the end portion of the quartz crystal vibrating piece, a portion where the crystal structure is changed or destroyed inside the quartz crystal vibrating piece is created, and the vibration region of the quartz crystal vibrating piece is The manufacturing method of the crystal device characterized by including the process limited to an inner side rather than the said site | part . The lid made of a material that transmits light is used, and after the lid sealing step, the lid is transmitted to irradiate the inside of the crystal vibrating piece in the package with the laser light. The method for manufacturing a quartz crystal device according to claim 3 . Thickness sliding vibration type crystal vibrating piece,
A portion where the crystal structure is changed or destroyed is created by focusing the laser beam inside, and the vibration region is limited to the inside of the portion. Piece. A crystal device that houses a thickness-shear vibration type crystal resonator element in a package or case,
A portion where the crystal structure is changed or broken is created by focusing the laser beam inside the quartz crystal vibrating piece, and the vibration region is limited to the inside of the portion. And crystal device. A mobile phone device using a crystal device containing a thickness-shear vibration type crystal resonator element in a package or case,
A portion where the crystal structure is changed or destroyed is created by focusing the laser beam inside the quartz vibrating piece, and the vibrating region is limited to the inside of the portion by the quartz crystal device. A cellular phone device characterized in that a clock signal for control is obtained. An electronic device using a crystal device that houses a thickness-shear vibration type crystal resonator element in a package or case,
A portion where the crystal structure is changed or destroyed is created by focusing the laser beam inside the quartz vibrating piece, and the vibrating region is limited to the inside of the portion by the quartz crystal device. An electronic device characterized in that a clock signal for control is obtained.

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