JP5566647B2 - Piezoelectric device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a piezoelectric device including a piezoelectric vibrating piece including a quartz piece and a method for manufacturing the same.

  Conventionally, in consumer and industrial electronic devices such as watches, home appliances, various information / communication devices and OA devices, a piezoelectric vibrator, a piezoelectric vibrating piece and an IC chip are sealed in the same package as a clock source for the electronic circuit. Piezoelectric devices such as stopped oscillators and real-time clock modules are widely used. In particular, these piezoelectric devices have recently been required to be further reduced in size and thickness as the electronic equipment on which they are mounted is reduced in size and thickness.

  The tuning fork type piezoelectric device disclosed in Patent Document 1 is provided with a fixing portion in a surface mount type package. The piezoelectric vibrating piece is fixed to a fixing portion provided in the package with a conductive adhesive or solder.

  The tuning fork type piezoelectric device disclosed in Patent Document 2 has an internal space, a piezoelectric vibrating piece is held on a package in the internal space, and the internal space of the housing is hermetically sealed. ing. In this internal space, the piezoelectric vibrating piece is electromechanically joined to the package by the FCB (Flip Chip Bonding) method, that is, ultrasonic vibration, using conductive bumps. The piezoelectric vibrating piece and the package are electrically connected by ultrasonic bonding using conductive bumps.

JP 2007-202111 A JP 2009-055354 A

  Currently, electronic components are being miniaturized, and accordingly, piezoelectric devices are being miniaturized. Therefore, the space of the package for accommodating the tuning fork type crystal vibrating piece is narrowed, and the position where the crystal vibrating piece is mounted on the package is restricted.

  Therefore, in the case of the piezoelectric device using the conductive adhesive described in Patent Document 1, with the downsizing of the piezoelectric device, the bonding position for bonding the crystal vibrating piece of the electrode pad is further reduced. The bonding position of the crystal vibrating piece with the package is also limited. Further, although it is necessary to heat the conductive adhesive when it is cured, stress may be applied to the crystal vibrating piece due to the difference in thermal expansion between the crystal vibrating piece and the metal film, and the frequency characteristics may fluctuate.

  In the case of a piezoelectric device in which a crystal vibrating piece is electromechanically joined to a package by the FCB method described in Patent Document 2, in order to hold the crystal vibrating piece and perform ultrasonic vibration by the FCP method, the crystal vibrating piece A holding jig for holding the sheet must enter the package. When the package is downsized, there arises a problem that an area in which the holding jig enters cannot be secured in the package. Further, when the FCB method is performed, it is necessary to heat the entire crystal vibrating piece and the package.

  An object of the present invention is to provide a piezoelectric device capable of bonding a piezoelectric vibrating piece and a package with a laser beam by a bump, and a manufacturing method thereof.

  A piezoelectric device according to a first aspect includes a pair of vibrating arms having an excitation electrode and extending from a base, and a pair of support arms having connection electrodes electrically connected to the excitation electrode and extending from the base on both outer sides of the vibrating arm. A tuning fork type piezoelectric vibrating piece made of a piezoelectric material and a base portion on one side on which a pair of bumps are formed are provided. In the piezoelectric device, the bump is melted by irradiating the bump with the laser in a state where the connection electrodes of the pair of support arms are placed on the pair of bumps, and then the bump is cured, so that the support arm becomes the base. Fixed.

  In the piezoelectric device according to the second aspect, the surface of the piezoelectric material appears on the opposite surface where the connection electrode of the support arm contacts the bump to form an exposed region.

  In the piezoelectric device according to the third aspect, a reference mark for confirming the laser irradiation position is formed on the opposite surface where the connection electrode of the support arm contacts the bump.

The reference mark of the piezoelectric device according to the fourth aspect is formed by surrounding the exposed region with a metal film.
In the piezoelectric device according to the fifth aspect, one side of the base portion on which the bump is formed has a support bump that supports the tuning fork type piezoelectric vibrating piece so that the tuning fork type piezoelectric vibrating piece is parallel to the one side.

  According to a sixth aspect of the present invention, there is provided a piezoelectric device manufacturing method comprising: a step of preparing a base portion on one side on which a pair of bumps are formed; a pair of vibrating arms having an excitation electrode and extending from a base; A step of preparing a tuning fork-type piezoelectric vibrating piece made of a piezoelectric material having electrodes and a pair of support arms extending from the base on both outer sides of the vibrating arm; and a mounting for mounting the pair of supporting arms on a pair of bumps A placing step, an irradiation step of irradiating the pair of bumps with a laser, and a lid joining step for joining the lid portion to the base portion.

  In the piezoelectric device manufacturing method according to the seventh aspect, the reference mark for confirming the laser irradiation position is formed on the opposite surface where the connection electrode of the support arm is in contact with the bump, and image processing for imaging and processing the reference mark The process includes a process, and the irradiation process irradiates a laser based on the result of the image processing.

  The present invention relates to a piezoelectric device that can join a crystal vibrating piece and a package with bumps and efficiently irradiate the bumps with laser light, and a method for manufacturing the piezoelectric device.

It is a side view of the 1st crystal oscillator 10A of a 1st embodiment. It is a top view of 10 A of 1st crystal oscillators of 1st Embodiment. It is an expanded sectional view of the part shown by BB of FIG. It is a flowchart for demonstrating the manufacturing method of 10 A of 1st crystal oscillators. It is a top view of the 2nd crystal oscillator 10B of a 2nd embodiment. It is a top view of the 3rd crystal oscillator 10C of a 3rd embodiment. It is a top view of 4th crystal oscillator 10D of 4th Embodiment. It is an expanded sectional view of the part shown by CC of FIG. It is a top view of the 5th crystal oscillator 10E of a 5th embodiment. It is a flowchart for demonstrating the manufacturing method of the 5th crystal oscillator 10E. It is a top view of the 6th crystal oscillator 10F of a 6th embodiment. It is a top view of the 7th crystal oscillator 10G of a 7th embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
In the following embodiments, a quartz resonator including a tuning fork type quartz vibrating piece as a piezoelectric device will be described as an example.

(First embodiment)
<First Crystal Resonator 10A>
The first crystal resonator 10A of the first embodiment will be described with reference to FIGS. FIG. 1 is a side view of the first crystal resonator 10A of the first embodiment. FIG. 2 is a plan view of the first crystal unit 10A of the first embodiment, and the lid 21 is omitted for ease of explanation.
The surface on which the first tuning-fork type piezoelectric vibrating piece 100A made of the crystal piece 11 is placed is an XY plane, and the direction in which the pair of vibrating arms 13 of the first tuning-fork type piezoelectric vibrating piece 100A is extended is the Y-axis direction. The direction perpendicular to the XY plane is taken as the Z-axis direction.

  The first crystal unit 10 </ b> A includes a base unit 22 and a lid body 21. The first tuning-fork type crystal vibrating piece 100A made of the crystal piece 11 is accommodated in this package. In the package outline of the first crystal unit 10A, the length L1 in the Y-axis direction is set to 2.0 mm, the width L2 in the X-axis direction is set to 1.2 mm, and the height H1 in the Z-axis direction is 0. .38mm is set. In the internal space of the package, the length L3 in the Y-axis direction is set to 1.6 mm, the width L4 in the X-axis direction is set to 0.8 mm, and the height H2 in the Z-axis direction is set to 0.26 mm. Has been.

  The base portion 22 is made of, for example, a piezoelectric body, ceramic, or glass. Conductive paths 27 a and 27 b are formed on the inner side of the base portion 22, and external electrodes 23 a and 23 b are formed on the bottom surface of the base portion 22. The lid 21 is made of borosilicate glass or a flat metal such as an Fe—Ni alloy (42 alloy) or an Fe—Ni—Co alloy (Kovar). The lid 21 is bonded to the base portion 22 by a bonding material 24 such as AuSi, AuS, or AuGe, and the inside of the package is hermetically sealed by a technique such as seam welding with nitrogen gas or vacuum. This is to prevent the electrodes of the first tuning-fork type crystal vibrating piece 100A from being easily oxidized.

  Further, a bonding material 24 made of a metal material is used for bonding the lid 21 and the base portion 22. The bonding material 24 has a thickness of 15 μm, and the bonding material 24 is formed on the entire surface of the lid 21 by means such as rolling. The lid body 21 is joined to the base portion 22 by a technique such as seam welding, beam welding, heat fusion joining, etc. via the joining material 24, and the first crystal resonator 10 </ b> A is formed by the lid body 21 and the base portion 22. A package is configured. Note that the bonding material 24 has a structure in which, for example, nickel and gold are plated in this order on a tungsten metallized layer or a molybdenum metallized layer.

  The outer shape of the first tuning-fork type crystal vibrating piece 100A is formed by etching. More specifically, the outer shape of a large number of first tuning-fork type crystal vibrating pieces 100A is formed simultaneously from a round or square crystal wafer. The outer shape of the first tuning-fork type crystal vibrating piece 100A is a first tuning-fork type crystal vibrating piece 100A using, for example, a hydrofluoric acid solution as an etching solution for a quartz wafer exposed from the mask using a mask such as a corrosion-resistant film (not shown). Wet etching of the outer shape is performed. As the corrosion-resistant film, for example, a metal film in which gold (Au) is vapor-deposited with nickel (Ni) as a base can be used. The time required for this etching process varies depending on the concentration, type, temperature, etc. of the hydrofluoric acid solution.

  By wet etching, a vibrating arm 13 having a first width W1 extending substantially in parallel from the base portion 18 is formed, and groove portions 14 are formed on both front and back surfaces thereof. More specifically, the length LK of the base 18 is about 0.15 mm, and the length KH of the pair of vibrating arms 13 is about 1.3 mm. Further, the width of the groove portion 14 in the X-axis direction is about 80% of the first width W1 of the vibrating arm 13 in the X-axis direction. One groove portion 14 is formed on the surface of one vibrating arm 13, and one groove portion 14 is similarly formed on the back surface side of the vibrating arm 13. That is, four groove portions 14 are formed in the pair of vibrating arms 13. For this reason, the cross section of the groove part 14 is formed in a substantially H shape, and has the effect of reducing the CI value of the first tuning-fork type crystal vibrating piece 100A. In the first embodiment, two groove portions 14 are formed on the front and back of one vibrating arm, but the same effect can be obtained by forming two groove portions. The second width W2 that is the distance in the X-axis direction between the pair of vibrating arms 13 is preferably the same as the first width W1 of the vibrating arms 13.

  Further, the base portion 18 of the first tuning-fork type crystal vibrating piece 100 </ b> A includes support arms 15 at both ends, and the length of the support arm 15 is shorter than the length of the vibration arm 13. The support arm 15 is suddenly widened and has a hammer-type tip 17. The hammer-type tip portion 17 is fixed to the base portion 22 via a bonding bump 26a described later. The width of the support arm 15 is substantially the same as the first width W1 of the vibrating arm 13, and the width of the hammer-type tip 17 is preferably 1.5 to 2 times the first width W1.

  A base electrode 19 and an excitation electrode 20 are formed on the base 18 and the vibrating arm 13. Connection electrodes 12a and 12b are provided on both sides of the support arm 15 on the Z side. The base electrode 19, the excitation electrode 20, and the connection electrodes 12a and 12b are formed in a two-layer structure in which an Au film is provided on a base made of, for example, a Ni film. Further, the electrode is formed by covering the entire surface with a metal to be an electrode by vapor deposition or sputtering, and then forming the electrode by a photolithography technique. The excitation electrode 20 is electrically connected to the connection electrodes 12 a and 12 b through the base electrode 19. The connection electrodes 12a and 12b are electrically connected to the conductive paths 27a and 27b via the bonding bumps 26a and are connected to the external electrodes 23a and 23b, respectively.

  As shown in FIG. 1, two bumps are supported on both sides of the inner surface of the base portion 22 in the X-axis direction so that the first tuning-fork type crystal vibrating piece 100 </ b> A is fixed to the inner surface of the base portion 22. A portion 25 is formed. Conductive paths 27 a and 27 b are formed on the bump support portion 25.

  As shown in FIG. 2, the base portion 22 has two bonding bumps 26 a and two support bumps 26 b formed on the inner surface of the base portion 22. The bonding bumps 26a and the support bumps 26b are made of, for example, gold (Au), AuSi, AuGe, AuSn, or the like, and have a diameter of 80 to 120 μm. The two bonding bumps 26a are formed on the conductive paths 27a and 27b, respectively. The two support bumps 26 b are respectively formed at positions that contact the support arm 15. Here, the two support bumps 26b serve to hold the first tuning fork type piezoelectric vibrating piece 100A without being joined to the first tuning fork type piezoelectric vibrating piece 100A. For this reason, the two support bumps 26b need to be arranged closer to the base 18 side than the center of gravity of the first tuning-fork type crystal vibrating piece 100A in the Y-axis direction so as not to support and tilt the first tuning-fork type crystal vibrating piece 100A. .

  As will be described later, the two bonding bumps 26a on the −X side are irradiated with the laser beam LL, so that the tip 17 of the support arm 15 of the first tuning-fork type piezoelectric vibrating piece 100A and the bonding bump 26a are bonded. .

  FIG. 3 is an enlarged cross-sectional view of a portion indicated by BB in FIG. FIG. 3 is a view showing a state in which the laser beam LL from the laser light source device LX is irradiated to the bonding bump 26a. As shown in FIG. 3, the laser light source device LX includes one or a plurality of laser light sources LM (or a tip portion guided from the laser light source LM with an optical fiber) and an elliptical mirror EM.

  The elliptical mirror EM has a first focal point F1 and a second focal point F2. The laser beams LL from the plurality of laser light sources LM are irradiated from the first focal point F1 on the + Z side of the elliptical mirror EM, and reflected to the −Z side by the elliptical mirror EM. Further, the bonding bump 26a is arranged at the second focal point F2 on the other −Z side of the elliptical mirror EM. Therefore, the laser beam LL irradiated to the first focal point F1 of the elliptical mirror EM is reflected by the inner surface of the elliptical mirror EM and is condensed again by the bonding bump 26a provided at the second focal point F2 of the elliptical mirror EM. Thereby, heat does not concentrate so much on the crystal piece 11, but heat concentrates only on the bonding bump 26a, and the bonding bump 26a melts well. At this time, a part of the connection electrode 12 formed on the upper surface side of the support arm 15 (that is, the surface opposite to the surface in contact with the bonding bump 26a) is not evaporated by the irradiation with the laser beam LL. Thereafter, when the irradiation of the laser light source LM stops, the bonding bump 26a is cured, and the first tuning-fork type crystal vibrating piece 100A is fixed to the inner surface of the base portion 22. The connection electrodes 12a and 12b are electrically connected to the conductive paths 27a and 27b through the bonding bumps 26a.

  Here, the second harmonic of the YAG laser is used as the laser light LL. The YAG laser is an infrared laser beam having a wavelength of 1064 nm that causes the YAG crystal to be excited by a lamp to oscillate, and its double harmonic is a green laser (wavelength of 532 nm). The laser light source device LX can irradiate a very small area with an extremely high energy density.

  Further, since the irradiation time of the YAG laser can be further reduced to about 3/1000 seconds to 20/1000 seconds, the crystal piece 11 or the connection electrodes 12a and 12b or the conductive paths 27a and 27b are deformed or distorted due to a thermal effect. Almost no nest (hole) is formed in the bump 26a after the joining bump 26a is joined, and the joining range can be suppressed to φ0.1 mm or less.

  In the first embodiment, the first tuning-fork type piezoelectric vibrating piece 100 </ b> A and the base portion 22 are supported by bonding bumps 26 a and bump support portions 25 formed on the bump support portions 25. However, the bump support portion 25 may be omitted, and the first tuning fork type piezoelectric vibrating piece 100 </ b> A and the base portion 22 may be bonded by providing the bonding bump 26 a on the inner surface of the base portion 22.

  In the first embodiment, the two support bumps 26b hold the first tuning fork type piezoelectric vibrating piece 100A without being joined to the first tuning fork type piezoelectric vibrating piece 100A. However, the two support bumps 26b may be joined to the first tuning-fork type piezoelectric vibrating piece 100A as joint bumps in the same manner as the joint bump 26a. That is, the four bonding bumps 26a may hold the first tuning fork type piezoelectric vibrating piece 100A.

<Method for Manufacturing First Crystal Resonator 10A>
FIG. 4 is a flowchart for explaining a manufacturing method of the first crystal resonator 10A.
In step S111, a base portion 22 having a pair of bump support portions 25 on the inner surface is prepared. On the bump support portion 25, conductive paths 27a and 27b that are electrically connected to the external electrodes 23a and 23b are formed. Bonding bumps 26a and support bumps 26b are provided on the conductive paths 27a and 27b, respectively.

  In step S112, a first tuning-fork type crystal vibrating piece 100A made of a crystal piece 11 having a pair of vibrating arms 13 and a pair of support arms 15 is prepared. The first tuning-fork type crystal vibrating piece 100 </ b> A has a pair of vibrating arms 13 in which grooves 14 are formed, and has support arms 15 having a wide end portion 17 on both outer sides of the vibrating arms 13. In addition, connection electrodes 12 a and 12 b are formed on the support arm 15.

In step S113, the first tuning-fork type crystal vibrating piece 100A is placed on the bonding bump 26a and the support bump 26b. The pair of support arms 15 are supported by the bonding bumps 26a and the support bumps 26b, and the first tuning-fork type crystal vibrating piece 100A is supported in parallel with the inner surface of the base portion 22.
In step S114, the laser light source device LX emits the laser light LL. The laser beam LL is focused on the bonding bump 26a on which the tip 17 of the support arm 15 is placed. The bonding bump 26a is disposed at the second focal point F2 of the elliptical mirror EM. Therefore, heat concentrates particularly on the bonding bump 26a, and the bonding bump 26a melts. When the laser light source device LX stops irradiating the laser beam LL, the bonding bump 26a is cured, and the first tuning-fork type crystal vibrating piece 100A is fixed to the inner surface of the base portion 22.

  In step S115, the frequency of the first tuning-fork type crystal vibrating piece 100A is adjusted. For example, by irradiating the tip of the vibrating arm 13 of the first tuning-fork type crystal vibrating piece 100A with laser light, a part of the metal coating is evaporated and sublimated to reduce the mass, thereby adjusting the vibration frequency.

  In step S <b> 116, the lid body 21 is joined to the base portion 22. The lid body 21 is joined to the base portion 22 by solder 24 such as AuSi, AuS, or AuGe, and the inside of the package is hermetically sealed by a technique such as seam welding with nitrogen gas or vacuum.

  In the flowchart, the laser light source device LX irradiates the laser beam LL and the first tuning-fork type crystal vibrating piece 100A is joined to the base portion 22 (step S114), and then the lid 21 is joined to the base portion 22. (Step S116). However, if the lid 21 is a transparent material such as a glass material, the laser beam LL is transmitted. Therefore, after the lid 21 is bonded to the base portion 22, the first tuning-fork type crystal vibrating piece 100 </ b> A may be bonded to the base portion 22 by irradiation with the laser beam LL. Furthermore, after the first tuning-fork type quartz vibrating piece 100A is joined to the base portion 22, the vibration frequency of the first tuning-fork type quartz vibrating piece 100A may be adjusted.

(Second Embodiment)
<Second crystal resonator 10B>
FIG. 5 is a plan view of the second crystal unit 10B of the second embodiment, and the lid 21 is omitted for easy explanation. In the second crystal resonator 10B of the second embodiment, the same constituent elements as those of the first embodiment will be described with the same reference numerals.

  As shown in FIG. 5, compared to the first crystal unit 10A, the second crystal unit 10B is different in the shape of the bump support portions 35a and 35b and the arrangement position of the support bumps 36b. Therefore, the description of the first tuning-fork type crystal vibrating piece 100A and the like is omitted.

  In the case of the configuration shown in the first embodiment, when an impact in the −Z-axis direction occurs on the base 18 of the + Y side portion of the support bump 26b, a load in the + Z-axis direction is applied to the bonding bump 26a using the support bump 26b as a fulcrum. There is a risk of taking. Further, in the first embodiment, the contact portion between the support bump 26b and the support arm 15 is a portion where the width of the crystal of the support arm 15 is narrow, which may affect the strength.

  In the second embodiment, the support bump 36b that supports the first tuning-fork type crystal vibrating piece 100A is disposed farthest from the bonding bump 26a on the + Y side. Since the support bump 36b that supports the first tuning-fork type crystal vibrating piece 100A is disposed on the + Y side of the base 18 away from the bonding bump 26a, the load in the + Z-axis direction on the bonding bump 26a can be reduced. In addition, since the support bump 36b is in contact with the wide base 18, the support bump 36b in the first tuning-fork type crystal vibrating piece 100A is compared with the case where the support bump 36b is formed at a position in contact with the support arm 15. The strength of the contact portion can be ensured.

  Further, as the arrangement positions of the bonding bumps 26a and the support bumps 36b change, the shapes and arrangement positions of the bump support portions 35a and 35b that support them also change. More specifically, two bump support portions 35a for supporting the first tuning fork type crystal vibrating piece 100A and the pair of bonding bumps 26a are provided immediately below the Z side. Further, one support portion 35b is provided directly below the Z side of the pair of support bumps 36b that are not joined to the first tuning-fork type crystal vibrating piece 100A. Here, two support portions 35b for supporting the support bumps 36b may be provided immediately below the Z side of the pair of support bumps 36b.

  Since the manufacturing method of the second crystal unit 10B is the same as that of the first embodiment, the description thereof is omitted.

(Third embodiment)
<Third crystal resonator 10C>
FIG. 6 is a plan view of the third crystal resonator 10C of the third embodiment, and the lid 21 is omitted for ease of explanation. In the third crystal resonator 10C of the third embodiment, the same constituent elements as those of the first embodiment will be described with the same reference numerals.

  As shown in FIG. 6, the third crystal resonator 10C differs from the first crystal resonator 10A in the shape of the bump support portion 35b and the arrangement position of the support bump 46b.

  In the third embodiment, the support bump 46 b that supports the first tuning-fork type crystal vibrating piece 100 </ b> A is disposed at the center of the end of the base 18 on the + X side. Accordingly, the first tuning-fork type crystal vibrating piece 100A is fixed in parallel to the inner surface of the base portion 22 by the bonding bumps 26a and the support bumps 46b.

  Further, as the arrangement positions of the bonding bumps 26a and the support bumps 46b are changed, the shapes and arrangement positions of the bump support portions 35a and 35b that support them are also changed. More specifically, two bump support portions 35a for supporting the first tuning fork type crystal vibrating piece 100A and the pair of bonding bumps 26a are provided immediately below the Z side. Also, one support portion 35b is provided directly below the Z side of the support bump 46b that is not joined to the first tuning-fork type crystal vibrating piece 100A.

  Here, if the size of the support bump 46b is too large, the two base electrodes 19 are short-circuited, and the first tuning-fork type crystal vibrating piece 100A cannot oscillate. Therefore, the size of the support bump 46b and the shape of the two base electrodes 19 It is necessary to consider. Since only one support bump 46b is required, the manufacturing cost of the third crystal unit 10C is reduced.

  Since the manufacturing method of the third crystal resonator 10C is the same as that of the first embodiment, the description thereof is omitted.

(Fourth embodiment)
<4th crystal unit 10D>
FIG. 7 is a plan view of the fourth crystal resonator 10D of the fourth embodiment, and the lid 21 is omitted for ease of explanation. FIG. 8 is an enlarged cross-sectional view of a portion indicated by CC in FIG. In the fourth crystal resonator 10D of the fourth embodiment, the same constituent elements as those of the first embodiment will be described with the same reference numerals.

  As shown in FIG. 7, the fourth crystal resonator 10D is different from the first crystal resonator 10A in the fourth tuning fork type crystal resonator element 100D. For this reason, description of other packages is omitted.

  The fourth tuning-fork type crystal vibrating piece 100D of the fourth embodiment is different in the shape of the connection electrode of the distal end portion 17 of the support arm 15. More specifically, the distal end portion 17 of the support arm 15 is not provided with connection electrodes on both surfaces in the Z-axis direction. As shown in FIG. 8, connection electrodes 42 a and 42 b are provided on the surface side of the tip 17 of the support arm 15 that is in contact with the bonding bump 26 a. No connection electrode is formed on the tip portion 17 on the upper surface side of the tip portion 17 (the surface opposite to the surface in contact with the bonding bump 26a). The connection electrode may not be formed not only on the tip portion 17 but also on the entire support arm 15.

  As shown in FIG. 8, when the laser light source device LX irradiates the laser light LL, only the crystal piece 11 at the tip portion 17 appears and there is no connection electrode. There is no reflection. For this reason, most of the energy of the laser beam LL is concentrated on the bonding bump 26a.

  Since the manufacturing method of the fourth crystal unit 10D is the same as that of the first embodiment, the description thereof is omitted. The connection electrodes 42a and 42b can also be formed by a photolithography technique.

(Fifth embodiment)
<Fifth crystal unit 10E>
FIG. 9 is a plan view of the fifth crystal unit 10E of the fifth embodiment, and the lid 21 is omitted for ease of explanation. In the fifth crystal unit 10E of the fifth embodiment, the same constituent elements as those of the first embodiment will be described with the same reference numerals.

  As shown in FIG. 9, the fifth crystal resonator 10E is different from the first crystal resonator 10A only in the fifth tuning-fork type crystal resonator element 100E. For this reason, description of other packages is omitted.

  Compared to the first tuning-fork type quartz vibrating piece 100A, the fifth tuning-fork type quartz vibrating piece 100E is different in the shape of the connection electrode of the tip 17 of the support arm 15. A reference mark 28 is provided on the opposite surface of the tip 17 of the support arm 15 in contact with the bonding bump 26a to confirm the irradiation position of the laser beam LL.

  In the fifth tuning-fork type crystal vibrating piece 100E, the reference mark 28 is a round reference mark. The reference mark 28 is formed as a round hole in a part of the connection electrodes 52 a and 52 b provided on the upper surface of the tip 17 of the support arm 15. In other words, the connection electrodes 52a and 52b are formed around the reference mark 28, and the round reference mark 28 is formed with the surface of the crystal piece appearing.

  Next to the laser light source device LX (see FIG. 8), an imaging device (not shown) that images the reference mark 28 is arranged. The imaging apparatus includes a CCD camera and an image processing apparatus that processes an imaging screen captured by the CCD camera. Based on the image processing result of the image processing apparatus, the position of the reference mark 28 on the XY plane can be confirmed. Thereby, the laser light LL can be adjusted to pass the reference mark 28 by moving the laser light source device LX or the fifth crystal unit 10E. For this reason, even if the joining bump 26a is small, the laser beam LL can be accurately irradiated to the joining bump 26a. The reference mark 28 is the surface of the crystal piece and the laser beam LL is not reflected. Therefore, when the laser beam LL is irradiated by the laser light source device LX, most of the energy of the laser beam LL is concentrated on the bonding bump 26a.

<Method for Manufacturing Fifth Crystal Resonator 10E>
FIG. 10 is a flowchart for explaining a method of manufacturing the fifth crystal unit 10E.
In step S211, a base portion 22 having a pair of bump support portions 25 on the inner surface is prepared. A base portion 22 having a pair of bump support portions 25 on the inner surface is prepared. Conductive paths 27 a and 27 b are formed on the bump support portion 25. Bonding bumps 26a and support bumps 26b are provided on the conductive paths 27a and 27b, respectively.

  In step S212, a fifth tuning-fork type crystal vibrating piece 100E made of a piezoelectric material having a pair of vibrating arms 13 and a pair of support arms 15 is prepared. The first tuning-fork type crystal vibrating piece 100 </ b> A has a pair of vibrating arms 13 in which grooves 14 are formed, and has support arms 15 having a wide end portion 17 on both outer sides of the vibrating arms 13. Further, connection electrodes 52 a and 52 b are formed on the support arm 15. Round reference marks 28 are respectively formed at the distal end portions 17 of the pair of connection electrodes 52a and 52b.

  In step S213, an image pickup device (not shown) arranged next to the laser light source device LX picks up the bonding bump 26a, and an image processing device (not shown) on the XY plane of the bonding bump 26a based on the picked-up image. Calculate the position.

  In step S214, based on the position of the bonding bump 26a, the fifth tuning-fork type crystal vibrating piece 100E is placed on the bonding bump 26a and the support bump 26b.

  In step S215, the imaging device images the reference mark 28 provided on the support arm 15, and the image processing device calculates the position of the reference mark 28 on the XY plane.

  In step S216, the irradiation position of the laser beam LL is confirmed based on the position of the reference mark 28 by the image processing apparatus. Thereafter, the laser light source device LX emits the laser light LL. The laser beam LL is focused on the bonding bump 26a on which the tip 17 of the support arm 15 is placed. The bonding bump 26a is disposed at the second focal point F2 of the elliptical mirror EM. Therefore, heat concentrates particularly on the bonding bump 26a, and the bonding bump 26a melts. When the laser light source device LX stops the irradiation of the laser beam LL, the bonding bump 26a is cured, and the fifth tuning-fork type crystal vibrating piece 100E is fixed to the inner surface of the base portion 22.

In step S217, the frequency of the fifth tuning-fork type crystal vibrating piece 100E is adjusted. By irradiating the tip of the vibrating arm 13 of the fifth tuning-fork type crystal vibrating piece 100E with a laser beam, the vibration frequency is adjusted by evaporating and sublimating a part of the metal coating to reduce the mass.
In step S <b> 218, the lid body 21 is joined to the base portion 22.

(Sixth embodiment)
<Sixth crystal unit 10F>
FIG. 11 is a plan view of the sixth crystal resonator 10F of the sixth embodiment, and the lid 21 is omitted for ease of explanation. In the sixth crystal resonator 10F of the sixth embodiment, the same constituent elements as those of the fifth embodiment will be described with the same reference numerals.

Compared to the fifth tuning-fork type quartz vibrating piece 100E, the sixth tuning-fork type quartz vibrating piece 100F is different in connection electrode of the tip 17 of the support arm 15. More specifically, a “+” type reference mark 38 is provided instead of the circular reference mark 28.
In the sixth tuning-fork type crystal vibrating piece 100 </ b> F, the reference mark 38 is formed with “ten” holes in a part of the connection electrodes 52 a and 52 b provided on the upper surface of the distal end portion 17 of the support arm 15. In other words, the connection electrodes 52 a and 52 b are formed around the reference mark 38, and the “ten” type reference mark 38 is formed by the surface of the crystal piece appearing.

  Since the other configuration and the method for manufacturing the crystal unit are the same as those in the fifth embodiment, description thereof is omitted.

(Seventh embodiment)
<Seventh crystal unit 10G>
FIG. 12 is a plan view of the seventh crystal unit 10G of the seventh embodiment, and the lid 21 is omitted for ease of explanation. In the seventh crystal resonator 10G of the seventh embodiment, the same constituent elements as those of the first embodiment are denoted by the same reference numerals.

  As shown in FIG. 12, the seventh crystal resonator 10G is different from the first crystal resonator 10A only in the seventh tuning-fork type crystal resonator element 100G. For this reason, description of other packages is omitted.

  The seventh tuning-fork type crystal vibrating piece 100G of the seventh embodiment has a pair of tuning-fork type vibrating arms 33 on the base 18, the length LK of the base 18 is about 0.15 mm, and the length of the pair of vibrating arms 33. Is about 1.3 mm long.

  The vibrating arm 33 extends in the X direction substantially parallel to the base portion 18, and grooves 34 are formed on both front and back surfaces of the vibrating arm 33. For example, two grooves 34 a and 34 b are formed on the surface of one vibrating arm 33, and two grooves 34 a and 34 b are similarly formed on the back side of the vibrating arm 33. Excitation electrodes are formed on the front and back surfaces and side surfaces of the vibrating arm 33. That is, the cross section of the groove 34 is formed in a substantially H shape and has an effect of reducing the CI value of the seventh tuning-fork type quartz vibrating piece 100G.

  The resonating arm 33 extending from the base portion 18 is gradually narrowed from the base portion to form a first constricted portion 71 (the width W1 'is larger than the width W1). This moves the stress concentrated in the root portion of the vibration arm 33 toward the first constricted portion 71, thereby reducing vibration leakage to the base portion 18. Further, the vibrating arm 33 gradually narrows from the first constricted portion 71 to form a second constricted portion 72 near the tip of the vibrating arm 33. The vibrating arm 33 is suddenly widened at the second constricted portion 72, and has a hammer shape with a width that does not allow the vibrating arms to collide with each other.

  Since it narrows in two steps from the wide root portion of the vibrating arm 33 to the first constricted portion 71 or the second constricted portion 72, the stress concentrated on the root portion moves in the distal direction of the vibrating arm 33, Vibration leakage to the base 18 is reduced. Also, by adjusting the hammer width W5, which is the width of the hammer mold, the hammer length HL, which is the length of the hammer mold, and the base hammer length HS, which is the length from the base to the hammer mold, the increase in the CI value is suppressed. However, oscillation at the second harmonic can be prevented.

  The base 18 of the seventh tuning-fork type crystal vibrating piece 100G includes support arms 75 at both ends. The base portion of the support arm 75 is formed wide (the width W1 'is larger than the width W1). The side surface of the support arm 75 on the vibrating arm 33 side is inclined to the Y direction side, and the width (Y direction) of the support arm 75 is narrowed from the root portion to form the third constricted portion 73. Further, the width of the support arm 75 gradually decreases from the third constricted portion 73, and the fourth constricted portion 74 is formed near the tip of the support arm 75. The support arm 75 is suddenly widened at the fourth constricted portion 74 and has a hammer shape. The support arm 75 is formed with connection electrodes 72a and 72b. The hammer-shaped portion protrudes toward the vibrating arm 33. The support arm 75 has a function of alleviating vibration leakage by gradually becoming narrower than the third constricted portion 73.

  Since the first width W1, the second width W2, and the third width W3 are the same as those described in the first embodiment, the seventh tuning-fork type crystal vibrating piece 100G that is balanced on the left and right is formed. be able to.

  The length of the support arm 75 is shorter than the length of the vibrating arm 33, and a metal film is formed at the tip of the vibrating arm 33 simultaneously with the excitation electrode. The metal film at the tip of the vibrating arm 33 acts as a weight to make the vibrating arm stably vibrate. Moreover, Q value improves by vibrating stably. The metal film at the tip of the vibrating arm 33 is formed to facilitate frequency adjustment of the seventh tuning-fork type quartz vibrating piece 100G mounted as a piezoelectric device.

  Also in the seventh embodiment, the −Y side bonding bump 26a is connected to the external electrode 23a (see FIG. 1) by the conductive path 27a, and the + Y side bonding bump 26a is connected to the external electrode 23b (by the conductive path 27b). (See FIG. 1).

  Furthermore, in the seventh embodiment, a hammer type is formed at the tip of the vibrating arm 33, but the vibrating arm gradually widens from the second constricted portion 72 to the tip of the vibrating arm so that the vibrating arms do not collide with each other. It may be formed. Further, as in the fifth and sixth embodiments, a reference mark may be formed at the tip of the support arm.

  As described above, the optimal embodiment of the present invention has been described in detail. However, as will be apparent to those skilled in the art, the present invention can be implemented with various modifications and variations within the technical scope thereof. For example, the crystal resonator can use various piezoelectric single crystal materials such as lithium niobate in addition to quartz. In addition to the piezoelectric vibrator, the present invention can also be applied to a piezoelectric oscillator in which an IC incorporating an oscillation circuit is arranged on the base portion.

10A to 10G ... 1st to 7th crystal resonators 11 ... Crystal pieces 12a, 12b, 42a, 42b, 52a, 52b, 62a, 62b, 72a, 72b ... Connection electrodes 13, 33 ... Vibrating arms 14, 34a, 34b ... Grooves 15 and 75 ... support arms 17 and 77 ... tip 18 ... base 19 ... base electrode 20 ... excitation electrode 21 ... lid body 22 ... base parts 23a and 23b ... external electrodes 24 ... bonding material 25 ... bump support part 26a ... bonding Bumps 26b, 36b, 46b, ... Support bumps 27a, 27b ... Conductive paths 28, 38 ... Round reference marks, "ten" -type reference marks 71 ... First constriction part, 72 ... Second constriction part, 73 ... First Three constricted portions 74 74 Fourth constricted portions 100A to 100G First to seventh tuning-fork type crystal vibrating pieces 100G
EM ... Elliptical mirror F1, F2 ... Focal point of H1 ... Outer height of base part, H2 ... Inner height of base part HL ... Length of hammer mold, HS ... Base hammer length HS
L1 ... outer length of the base part, L2 ... outer width of the base part L3 ... inner length of the base part, L4 ... inner width of the base part LK ... length of the base part LL ... laser light LM ... laser light source LX ... laser light source device W1 ... The width of the vibrating arm, W2 ... the distance between the vibrating arms, W3 ... the width of the tip of the supporting arm, W4 ... the distance between the vibrating arm and the supporting arm, W5 ... the hammer-type width of the vibrating arm of the seventh embodiment

Claims (4)

A tuning fork type composed of a piezoelectric material having a pair of vibrating arms having excitation electrodes and extending from the base, and a pair of support arms extending from the base on both outer sides of the vibrating arms having connection electrodes electrically connected to the excitation electrodes. A piezoelectric vibrating piece;
On one side, and a base portion having a pair of support bumps corresponding to the base side of the pair of bonding the bumps and the support arm corresponding to the tip end remote from the base portion of the support arm,
When the connection electrodes of the pair of support arms are placed on the pair of bonding bumps, the bonding bumps are melted by irradiating the bonding bumps with a laser, and then the bonding bumps are cured to support the support. The arm is fixed to the base part,
The support bump is a piezoelectric device that supports the support arm so that the tuning-fork type piezoelectric vibrating piece is parallel to the one surface and is not bonded to the support arm . The piezoelectric device according to claim 1, wherein a surface of the piezoelectric material appears on an opposite surface where the connection electrode of the support arm is in contact with the bonding bump to form an exposed region. The piezoelectric device according to claim 2, wherein a reference mark for confirming an irradiation position of the laser is formed on an opposite surface where the connection electrode of the support arm is in contact with the bonding bump. The piezoelectric device according to claim 3, wherein the reference mark is formed by surrounding the exposed region with a metal film.