JP2009124370A - Piezoelectric vibrator and piezoelectric device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a piezoelectric vibrator or piezoelectric device, wherein variation of CI values is made smaller and variation of apex temperature is improved. <P>SOLUTION: The piezoelectric device (50) includes: a tuning fork type piezoelectric vibrator (20) having a base electrode which conducts with an excitation electrode formed in an oscillation arm (21); an insulating package (51) which forms cavity for mounting the tuning fork type piezoelectric vibrator inside and has an external terminal (82) outside; a connection terminal (81) formed inside the insulating package and connected from the external terminal; an insulating layer (87) which covers a part of the surface of the connection terminal; and a conductive adhesive (31) which conducts a base electrode with the connection terminal, and fixes the tuning fork type piezoelectric vibrator. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement of a piezoelectric vibrating piece and a piezoelectric device that accommodates the piezoelectric vibrating piece in a package.

  Piezoelectric devices such as piezoelectric vibrating reeds and piezoelectric oscillators are widely used in small information devices such as HDDs (hard disk drives), mobile computers, IC cards, and clock sources for mobile phones.

The tuning fork type piezoelectric vibrating piece disclosed in Patent Document 1 forms a tuning fork type outer shape by wet etching a piezoelectric material such as a quartz wafer. In order to lower the crystal impedance (CI) value of the tuning fork type piezoelectric vibrating piece, the relationship between the width and thickness of the pair of vibrating arms is adjusted. Further, in Patent Document 2, in order to stabilize the CI value variation (standard deviation σ) of the tuning fork type piezoelectric vibrating piece and reduce the size, a groove is formed in the vibrating arm and a notch is formed in the base. Variations in CI values between elements are reduced.
JP2001-203560 JP 2004-266871 A

  However, as shown in Patent Document 2, even a tuning fork type piezoelectric vibrating piece having a notch formed in the base portion still has a large variation in CI value, and even compared with a tuning fork type piezoelectric vibrating piece having no notch. The value variation is not greatly improved. Moreover, the variation in the peak temperature is large, and many tuning-fork type piezoelectric vibrating reeds that do not meet the standards have been generated as defective products during product inspection.

  Accordingly, the present invention has been made to solve the above-described problems, and provides a piezoelectric vibrating piece or a piezoelectric device in which the variation in CI value is further reduced and the variation in apex temperature is improved in downsizing. Objective.

A piezoelectric device according to a first aspect includes a tuning fork type piezoelectric vibrating piece having a base electrode electrically connected to an excitation electrode formed on a vibrating arm, a cavity for mounting the tuning fork type piezoelectric vibrating piece on an inner surface, and an outer surface on an outer surface. An insulating package having terminals, a connection terminal formed on the inner surface of the insulating package and connected from an external terminal, an insulating layer covering a part of the surface of the connection terminal, the base electrode and the connection terminal are electrically connected and a tuning fork And a conductive adhesive that fixes the piezoelectric vibrating piece.
According to the configuration of the first aspect, since a part of the surface of the connection terminal is covered with the insulating layer, the variation of the CI value is reduced and the variation of the vertex temperature is also reduced. For this reason, the occurrence rate of defective products is reduced by inspection of CI value or vertex temperature.

In the piezoelectric device according to the second aspect, the region where the connection terminal and the conductive adhesive are conducted is smaller than the application area of the conductive adhesive.
According to the configuration of the second aspect, even when the piezoelectric vibrating piece is bonded and fixed without changing the amount of the conductive adhesive applied, the region where the connection terminal is electrically connected to the conductive adhesive is conductive because of the insulating layer. Smaller than the area of the adhesive adhesive application region.

In the piezoelectric device according to the third aspect, the region where the connection terminal and the conductive adhesive are conducted is formed in a circular or rectangular shape by the insulating layer.
According to the configuration of the third aspect, the region where the connection terminal and the conductive adhesive are conducted is smaller than the area of the conductive adhesive application region.

A piezoelectric device according to a fourth aspect. The insulating layer is formed of silicon dioxide (SiO ₂ ) or aluminum oxide (Al ₂ O ₃ ). According to the configuration of the piezoelectric device according to the fourth aspect, the silicon dioxide or aluminum oxide is a connection electrode, particularly gold plating or gold bump. It is an insulating layer that is easy to bond to.

In the piezoelectric device according to the fifth aspect, a bump is formed on the surface of the connection terminal, and the bump and the conductive adhesive are conducted.
According to the configuration of the fifth aspect, a piezoelectric device in which bumps are formed on the surface of the connection terminal may be used.

The connection terminal of the piezoelectric device according to the sixth aspect includes a first connection terminal and a second connection terminal, and the first connection terminal and the second connection terminal are each covered with an insulating layer.
According to the configuration of the sixth aspect, the insulating layer is not formed only on the first connecting terminal, but the first connecting terminal and the second connecting terminal are each covered with the insulating layer. The region where the connection terminal and the conductive adhesive are conducted can be made smaller.

In the piezoelectric device according to the seventh aspect, the region where the connection terminal is electrically connected to the conductive adhesive is 30% to 75% of the area of the application region.
According to the structure of the 7th viewpoint, if the area | region where a connection terminal conducts with a conductive adhesive is 30% or more, a piezoelectric vibrating piece can be actually fixed. On the other hand, as can be understood from FIG. 6, when the area where the connection terminal is electrically connected to the conductive adhesive is 80% or more, the variation σ of the vertex temperature (ZTC) becomes 1 or more, and the variation is large as in the conventional connection terminal. turn into.

  According to the present invention, by forming an insulating layer on the connection terminal in the package and reducing the region that is electrically connected to the conductive adhesive, it is possible to further reduce the variation in the CI value and the variation in the vertex temperature. .

<Configuration of crystal unit 50>
Hereinafter, a crystal resonator 50 according to each embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of a crystal resonator 50 according to the first embodiment of the present invention. 1A is an overall perspective view, FIG. 1B is a cross-sectional view, and FIG. 1C is a top view with the metal lid 71 removed.

  The surface-mount type crystal unit 50 includes an insulating ceramic package 51 and a metal lid 71 that covers the package of the crystal unit 50. The metal lid 71 is made of Kovar (iron (Fe) / nickel (Ni) / cobalt (Co) alloy). The ceramic package 51 includes a bottom ceramic layer 51a, a wall ceramic layer 51b, and a pedestal ceramic layer 51c that are pressed from a green sheet using a slurry containing a ceramic powder mainly composed of alumina, a binder, and the like. As a material of the ceramic package 51 constituting the package, glass ceramic may be used instead of ceramic powder mainly composed of alumina. As understood from FIG. 1B, the package composed of the plurality of ceramic layers 51 a to 51 c forms a cavity 58, and the tuning fork type crystal vibrating piece 20 is mounted in the cavity 58.

  A part of the upper surface of the pedestal ceramic layer 51c is formed with a connection terminal 81 that is electrically connected to the first base electrode 23a and the second base electrode 25a (see FIG. 2) of the tuning-fork type crystal vibrating piece 20. At least two external terminals 82 formed on the bottom surface of the ceramic package 51 are formed. The connection terminal 81 and the external terminal 82 are electrically connected by the through-hole wiring 83. A sealing material 37 is provided at the upper end of the wall ceramic layer 51 b and a metal lid 71 is joined thereto.

<Configuration of first piezoelectric vibrating piece>
FIG. 2A is a plan view showing an embodiment of the first tuning-fork type crystal vibrating piece 20 of the present invention. (B) is a BB cross-sectional view,
The first tuning-fork type crystal vibrating piece 20 is formed by cutting out a crystal single crystal wafer so as to become, for example, a crystal Z plate 10. In addition to quartz, piezoelectric materials such as lithium tantalate and lithium niobate can be used. The first tuning-fork type crystal vibrating piece 20 is a small vibrating piece that oscillates a signal at 32.768 KHz. Such a tuning-fork type crystal vibrating piece 20 has a base 29 and a pair of vibrating arms 21 protruding from the base 29 in the X direction. On the surface of the vibrating arm 21, two grooves 27 are formed in each vibrating arm 21 as shown in FIG. Since the groove 27 is formed on the back side of the vibrating arm 21 in the same manner, as shown in FIG. 2B, the sectional view of the groove 27 of the vibrating arm 21 is substantially H-shaped. The groove 27 is provided to suppress an increase in CI (crystal impedance) value.

  As shown in FIG. 2A, the entire base portion 29 of the first tuning-fork type crystal vibrating piece 20 is substantially plate-shaped. In the drawing, the length L2 in the vertical direction is, for example, 0.58 mm. On the other hand, in the figure of the vibrating arm 21 protruding from the base portion 29, the length L1 in the vertical direction is formed to be about 1.70 mm. Therefore, the length of the base portion 29 with respect to the vibrating arm 21 is about 34%. The arm width W3 of the vibrating arm 21 is about 0.12 mm.

  The base portion 29 forms a first base portion 29-1 and a second base portion 29-2 on each vibrating arm 21 side. The length (width) in the Y direction of the first base portion 29-1 is W1, and the width (width) of the second base portion 29-2 in the Y direction is wider than the width W1 of the first base portion 29-1. W2. The width W1 is about 75 to 90 percent of the width W2. For example, the width W1 is 0.42 mm and the width W2 is 0.50 mm. For this reason, the leakage vibration that has leaked from the groove 27 due to the vibration of the vibrating arm 21 is not easily transmitted to the second base 29-2.

  Moreover, the two connection parts 28 are formed in the 2nd base 29-2. The two connecting portions 28 are members that remain when the tuning fork type crystal vibrating piece 20 is cut from the crystal single crystal wafer. Generally, a single crystal single crystal wafer has several thousand first tuning fork type crystals. The vibration piece 20 is connected.

  A first electrode pattern 23 and a second electrode pattern 25 are formed on the vibrating arm 21 and the base 29 of the first tuning-fork type crystal vibrating piece 20. Both the first electrode pattern 23 and the second electrode pattern 25 have a structure in which a gold (Au) layer of 400 angstroms to 3000 angstroms is formed on a chromium (Cr) layer of 50 angstroms to 700 angstroms. A tungsten (W) layer or a titanium (Ti) layer may be used instead of the chromium (Cr) layer, and a silver (Ag) layer may be used instead of the gold (Au) layer. Moreover, it may consist of one layer, for example, an Al (aluminum) layer is used.

  A first base electrode 23a and a second base electrode 25a are formed on the base 29 of the tuning-fork type crystal vibrating piece 20, and a first groove electrode 23d and a second groove electrode 25d are formed in the groove 27 of the arm part 21, respectively. It is formed. The widths of the first groove electrode 23d and the second groove electrode 25d are equal to the arm width W3 of the vibrating arm 21. As shown in FIG. 2B, second side electrodes 25 c are formed on both side surfaces of the left vibrating arm 21. First side electrodes 23c are formed on both side surfaces of the right vibrating arm 21 (not shown). A first connection electrode 23b is formed to conduct the first base electrode 23a1, the first side electrode 23c, and the first groove electrode 23d, and the second base electrode 25a1, the second side electrode 25c, and the second groove electrode 25d are formed. The second connection electrode 25b is formed for electrical connection.

<Configuration of ceramic package 51>
Next, a method for manufacturing the ceramic package 51 will be described. 3A is a cross-sectional view taken along line AA of the ceramic package 51 shown in FIG. 3B, FIG. 3B is a top view, and FIG. 3C is a cross-sectional view taken along line CC in FIG.

  In the laminated and pressure-bonded ceramic package 51, a through hole 83 is formed for electrical connection between the front and back surfaces of the ceramic package 51. The through hole 83 is formed by filling a conductive paste made of a refractory metal such as tungsten (W) or molybdenum (Mo). The pair of connection terminals 81 on the cavity 58 side and the pair of external terminals 82 on the bottom side are also formed by thickly applying a conductive paste made of a refractory metal. Furthermore, the connection terminal 81 and the external terminal 82 are completed as a wiring by performing nickel (Ni) plating and gold (Au) plating on the connection terminal 81 and the external terminal 82 by electroplating.

Further, gold (Au) bumps 84 are formed on the connection terminals 81 and the external terminals 82 plated with gold in order to improve the conduction with the conductive adhesive 31. Further, an insulating layer 87 is formed on a part of the gold bump 84. The insulating layer 87 is preferably, for example, silicon dioxide (SiO ₂ ) or aluminum oxide (Al ₂ O ₃ ). The insulating layer 87 serves to reduce the area where the conductive adhesive 31 is conducted to the gold bump 84. Note that the insulating layer 87 shown in FIG. 3 is formed so that the conductive region through which the gold bump 84 conducts is circular, and its direct shape is φ0.01 mm to φ0.18 mm. Alternatively, the insulating layer 87 may be formed on the connection terminals 81 that are directly gold-plated without forming the gold bumps 84.

  A conductive adhesive 31 is applied on the gold bumps 84 and the insulating layer 87 in order to support the tuning fork type crystal vibrating piece 20 in a cantilevered manner horizontally with respect to the bottom surface. The conductive adhesive 31 includes epoxy, silicone, polyimide, polyurethane resin, or the like as a binder and is composed of a conductive filler such as silver, nickel, or carbon. The conductive adhesive 31 is applied to the application region illustrated in FIG. 3 so that the tuning fork type crystal vibrating piece 20 is not peeled off by an impact or the like. The application region of the conductive adhesive 31 has a length L11 of, for example, around 0.30 mm and a width W11 of 0.15 mm to 0.20 mm. If the coating area is smaller than this, the adhesive force is weak, and the tuning fork type crystal vibrating piece 20 may be peeled off by impact or the like.

<Shape of insulating layer formed on connection terminal>
The insulating layer 87 in FIG. 3 is formed so that the conductive region where the gold bumps 84 are conducted is circular, but may be formed in the shape of other conductive regions.
4 and 5 are enlarged views of the periphery of the ceramic ceramic layer 51c for the pedestal on the cavity 58 side of the ceramic package 51. FIG.

<< Embodiment 1 >>
In FIG. 4 (a), a connection terminal 81 is formed on the ceramic layer 51c for pedestals, a gold bump 84 is formed thereon, and an insulating layer 87a is further formed. The insulating layer 87a is formed so that the gold bumps 84 appear at both ends of the pedestal ceramic layer 51c. The length WA in the X direction of the gold bump 84 is about 0.01 mm to about 0.15 mm, and the length LA in the Y direction is 0.3 mm. Then, the conductive adhesive 31 is applied to the gold bump 84 and the insulating layer 87a, and the base 29 of the tuning fork type crystal vibrating piece 20 is bonded. For example, if the length WA in the X direction of the pair of left and right gold bumps 84 is about 0.05 mm, the region where the conductive adhesive 31 and the gold bump 84 are electrically connected is about 25 percent of the application region of the conductive adhesive 31. Become.

<< Embodiment 2 >>
In FIG. 4B, a connection terminal 81 is formed on the pedestal ceramic layer 51c, a gold bump 84 is formed thereon, and an insulating layer 87b is further formed. The insulating layer 87b is formed such that a gold bump 84 appears in the center of the pedestal ceramic layer 51c and its length in the Y direction is short. The length WB in the X direction of the gold bump 84 is about 0.01 mm to about 0.15 mm, and the length LB in the Y direction is 0.01 mm to about 0.3 mm. For example, if the length WB in the X direction of the pair of left and right gold bumps 84 is about 0.05 mm and the length LB in the Y direction is 0.15 mm, the region where the conductive adhesive 31 and the gold bumps 84 are electrically connected is conductively bonded. It becomes about 12 percent of the application area of the agent 31.

<< Embodiment 3 >>
In FIG. 4C, a connection terminal 81 is formed on the pedestal ceramic layer 51c, a gold bump 84 is formed thereon, and an insulating layer 87c is further formed. In this insulating layer 87c, a gold bump 84 extending in the center X direction of the pedestal ceramic layer 51c appears. The length WC in the X direction of the gold bump 84 is about 0.2 mm, and the length LC in the Y direction is 0.01 mm to 0.1 mm. For example, if the length LC in the Y direction of the pair of left and right gold bumps 84 is about 0.05 mm, the area where the conductive adhesive 31 and the gold bump 84 are electrically connected is about 18% of the area where the conductive adhesive 31 is applied. Become.

<< Embodiment 4 >>
FIG. 5A is an embodiment in which the shape of the insulating layer 87 formed on the pair of pedestal ceramic layers 51c is different on the left and right, unlike the first to third embodiments shown in FIG. . In FIG. 5A, the left insulating layer 87c is the same as the insulating layer 87c of the third embodiment, but the insulating layer 87 is not formed at all on the right pedestal ceramic layer 51c. In FIG. 5A, the left side is the insulating layer 87c of the third embodiment, but conversely, the insulating layer 87c of the third embodiment may be formed only on the right side. Furthermore, the insulating layer 87a of Embodiment 1 or the insulating layer 87b of Embodiment 2 may be formed. In the insulating layer 87 c only on one side in FIG. 5A, the region where the conductive adhesive 31 and the gold bump 84 are conducted is about 68% of the application region of both the conductive adhesives 31.

<< Embodiment 5 >>
In FIG. 5 (b), the connection terminal 81 and the gold bump 84 are formed on the ceramic layer 51c for the pedestal, and the insulating layer 87d is further formed. In this insulating layer 87d, rectangular gold bumps 84 appear in the central region of the pedestal ceramic layer 51c. The length of one side of the rectangular gold bump 84 is about 0.01 mm to about 0.15 mm. For example, if the length of one side of the rectangular gold bump 84 is about 0.05 mm, the region where the conductive adhesive 31 and the gold bump 84 are electrically connected is about 4 percent of the region where the conductive adhesive 31 is applied.

<Gold bump and CI value variation and vertex temperature variation (standard deviation σ)>
FIG. 6 shows the connection terminal 81 in which the insulating layer 87a of the first embodiment is formed and the connection terminal in which the insulating layer 87b of the second embodiment is formed with respect to the variation of the CI value and the variation of the apex temperature (standard deviation σ). This is a result of examining 81. The number of parameters examined was 30 each.

  FIG. 6A is a table showing a change in CI value for the connection terminal 81 on which the insulating layer 87a of the first embodiment is formed and the connection terminal 81 on which the insulating layer 87b of the second embodiment is formed. The vertical axis represents variation, and the horizontal axis represents the area ratio of the gold bumps 84 to the conductive adhesive 31. In addition, by changing the length LA and the length WA of the insulating layer 87a or the length LB and the length WB of the insulating layer 87b, the area ratio in which the conductive adhesive 31 and the gold bump 84 are conducted is changed to 30%. Varyed to 50 percent, 75 percent and 90 percent.

  FIG. 6B is a table showing a change in apex temperature (ZTC) with respect to the connection terminal 81 formed with the insulating layer 87a of the first embodiment and the connection terminal 81 formed with the insulating layer 87b of the second embodiment. It is. The vertical axis represents variation, and the horizontal axis represents the area ratio at which the conductive adhesive 31 and the gold bump 84 are conducted.

The conventional tuning fork type crystal vibrating piece had a CI value variation of 2.5 and a vertex temperature variation of 1.3.
On the other hand, in the crystal units 50 of the first and second embodiments, the variation in CI value and the variation in vertex temperature become smaller as the area ratio where the conductive adhesive 31 and the gold bump 84 are conducted decreases. It was. In particular, the connection terminal 81 on which the insulating layer 87a of the first embodiment is formed has smaller CI value variations and vertex temperature variations.

If the region where the conductive adhesive 31 and the gold bump 84 are conducted is 30% or more, the crystal vibrating piece 20 can be actually fixed to the pedestal ceramic layer 51c. Therefore, the conductive adhesive 31 and the gold bump 84 can be fixed. The minimum ratio of the area ratio that conducts is 30 percent. Conversely, if the area ratio where the conductive adhesive 31 and the gold bump 84 are conducted is 80% or more, the variation in the vertex temperature of the second embodiment is 1.0, and the conventional base electrode and The difference will be smaller. Therefore, the maximum limit of the area ratio at which the conductive adhesive 31 and the gold bump 84 are conducted is about 75%.
As can be understood from FIGS. 6A and 6B, the area ratio between the conductive adhesive 31 and the gold bumps 84 is particularly preferably 30% to 70%.

<Configuration of second piezoelectric vibrating piece>
FIG. 7 is a plan view showing an embodiment of the second tuning-fork type crystal vibrating piece 120 of the present invention. For members having the same configuration, the reference numerals used in FIG. 2 and the like are used. The second tuning-fork type crystal vibrating piece 120 can be made smaller in the Y direction than the first tuning-fork type crystal vibrating piece 20 by making the base 29 smaller.

  The second tuning-fork type crystal vibrating piece 120 is formed by cutting a crystal single crystal wafer so as to become the crystal Z plate 10. The second tuning-fork type crystal vibrating piece 120 is extended in the width direction of the base portion 29 on the way from the end where the vibrating arm 21 of the base portion 29 is formed to the two connecting portions 28, at positions on both outer sides of the vibrating arm 21. A supporting arm portion 29-3 extending in parallel with the vibrating arm 21 is provided. The electrode width W6 of the support arm 29-3 is narrowly formed from about 0.05 mm to about 0.08 mm. A wide area 29-4 for conductive adhesion is provided at the tip of the support arm 29-3. The wide area 29-4 has an electrode width W7 of about 0.14 mm to 0.20 mm and a length L7 of about 0.14 mm to 0.20 mm. The outer shape of the second tuning-fork type crystal vibrating piece 120 is precisely formed by wet etching or the like of a crystal single crystal wafer or the like.

  Even if the base portion 29 of the second tuning-fork type crystal vibrating piece 120 is made small, the support arm portion 29-4 is separated by a predetermined length. Almost never. In order to support the second tuning-fork type crystal vibrating piece 120, it is fixed with the conductive adhesive 31 in the wide area 29-4.

<Configuration of ceramic package 151>
FIG. 8 shows a ceramic package 151 for the second tuning-fork type crystal vibrating piece 120. 8A is a cross-sectional view taken along the line AA of the ceramic package 151 shown in FIG. 8B, FIG. 8B is a top view, and FIG. 8C is a cross-sectional view taken along the line CC in FIG. The configuration is almost the same as the ceramic package 51 for the first tuning-fork type crystal vibrating piece 20 described in FIG. 3, and the same reference numerals are given to the same members.

  The ceramic package 151 shown in FIG. 8 is different from the ceramic package 51 shown in FIG. 3 in the position of the pedestal ceramic layer 151c. A pair of connection terminals 81 made of a refractory metal such as tungsten (W) or molybdenum (Mo) is formed on the pedestal ceramic layer 151c. Further, the connection terminal 81 is completed as a wiring by performing nickel (Ni) plating and gold (Au) plating on the connection terminal 81 and the external terminal 82 by electroplating.

  Further, gold (Au) bumps 84 are formed on the connection terminals 81 and the external terminals 82 plated with gold. Further, an insulating layer 87 is formed on a part of the gold bump 84. The insulating layer 87 serves to reduce the area where the conductive adhesive 31 is conducted to the gold bump 84. Then, the conductive adhesive 31 is applied on the gold bumps 84 and the insulating layer 87 in order to support the second tuning-fork type crystal vibrating piece 120 in a cantilevered manner with respect to the bottom surface.

  In FIG. 8, the insulating layer 87 is formed so that the conductive region through which the gold bump 84 conducts is circular. However, as shown in FIGS. 4 to 5, the conductive adhesive 31 and the gold bump 84 are separated from each other. The conducting shape and area can be changed. Also in the ceramic package 151, the area ratio where the conductive adhesive 31 and the gold bump 84 are conducted is preferably about 1 to 80 percent. Such an insulating layer 87 has a small variation in CI value and a small variation in vertex temperature.

The schematic diagram of the crystal oscillator 50 concerning a first embodiment of the present invention is shown. (A) is an overall perspective view, (b) is a cross-sectional view, and (c) is a top view with the metal lid 71 removed. (A) is a diagram showing the overall configuration of the tuning-fork type crystal vibrating piece 20, and (b) is a BB cross-sectional view of one vibrating arm 21 of the tuning-fork type crystal vibrating piece 20. (A) is AA sectional drawing of the ceramic package 51 shown to (b). (B) is a top view, (c) is CC sectional drawing of (b). It is the figure which expanded the ceramic layer 51c periphery for the bases by the side of the cavity 58 of the ceramic package 51. As shown in FIG. It is the figure which expanded the ceramic layer 51c periphery for the bases by the side of the cavity 58 of the ceramic package 51. As shown in FIG. (A) is the table | surface which showed the change of CI value regarding the connecting terminal 81 in which the insulating layer 87a of 1st Embodiment was formed, and the connecting terminal 81 in which the insulating layer 87b of 2nd Embodiment was formed. (B) is a table showing changes in the vertex temperature (ZTC) with respect to the connection terminal 81 on which the insulating layer 87a of the first embodiment is formed and the connection terminal 81 on which the insulating layer 87b of the second embodiment is formed. . 5 is a plan view showing an embodiment of a second tuning-fork type crystal vibrating piece 120 of the present invention. FIG. This is a ceramic package 151 for the second tuning-fork type crystal vibrating piece 120. (A) is AA sectional drawing of the ceramic package 151 shown to (b), (b) is a top view, (c) is CC sectional drawing of (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Quartz Z board 20 ... Tuning fork type crystal vibrating piece 21 ... Vibrating arm 23 ... 1st electrode pattern (23a ... 1st base electrode, 23b ... 1st connection electrode, 23d ... 1st groove electrode, 23c ... 1st side electrode )
25 ... 2nd electrode pattern (25a ... 2nd base electrode, 25b ... 2nd connection electrode, 25c ... 2nd side electrode, 25d ... 2nd groove electrode)
27 ... Groove part 28 ... Connecting part 29 ... Base part (29-1 ... First base part, 29-2 ... Second base part, 29-3 ... Support arm part, 29-4 ... Wide area part)
31 ... Conductive adhesive 37 ... Sealing material 50 ... Crystal resonator 51, 151 ... Ceramic package (51a ... Bottom ceramic layer, 51b ... Wall ceramic layer, 51c, 151c ... Base ceramic layer)
58 ... Cavity 71 ... Metal lid 81 ... Connection terminal 82 ... External terminal 83 ... Through-hole wiring 84 ... Gold bumps 87, 87a, 87b, 87c ... Insulating layer 120 ... Second tuning-fork type crystal vibrating piece

Claims (7)

A tuning fork-type piezoelectric vibrating piece having a base electrode electrically connected to an excitation electrode formed on a vibrating arm;
An insulating package having a cavity for mounting the tuning fork type piezoelectric vibrating piece on the inner surface and having an external terminal on the outer surface;
A connection terminal formed on the inner surface of the insulating package and connected from the external terminal;
An insulating layer covering a part of the surface of the connection terminal;
A conductive adhesive for conducting the base electrode and the connection terminal and fixing the tuning-fork type piezoelectric vibrating piece;
A piezoelectric device comprising: 2. The piezoelectric device according to claim 1, wherein a region where the connection terminal and the conductive adhesive are conducted is smaller than an application area of the conductive adhesive. 3. The piezoelectric device according to claim 1, wherein a region where the connection terminal and the conductive adhesive are electrically connected is formed in a circular shape or a rectangular shape by the insulating layer. The piezoelectric device according to claim 1, wherein the insulating layer is formed of silicon dioxide (SiO ₂ ) or aluminum oxide (Al ₂ O ₃ ). 5. The piezoelectric device according to claim 1, wherein a bump is formed on a surface of the connection terminal, and the bump and the conductive adhesive are electrically connected. The connection terminal includes a first connection terminal and a second connection terminal,
The piezoelectric device according to claim 1, wherein the first connection terminal and the second connection terminal are each covered with the insulating layer. 7. The piezoelectric device according to claim 1, wherein a region in which the connection terminal is electrically connected to the conductive adhesive is 30% to 75% of the area of the application region. .