JPH1127084A - Crystal vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a crystal vibrator which can be easily formed on a flat printed circuit board with a vibration space secured and can stabilize its characteristic. SOLUTION: This crystal vibrator 1 includes the vibration electrodes 11 and 12 formed on both main surface of a strap-shaped crystal plate 10 and the electrode pads 11a and 12a which are extended from the electrodes 11 and 12 at least at one of both ends of the lower surface of the plate 10. Then the vibrator 1 is bonded on a printed circuit board 2 where a wiring pattern 5 including connection pads 5a and 5b is formed. In such a constitution, the vibrator 1 and the board 2 are bonded together at one of ends of them respectively by means of a fulcrum member 3 which touches and supports the lower surface of the vibrator 1 at one of its ends and a conductive resin adhesive 4 which is located outside the member 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quartz resonator having a strip-shaped quartz resonator substantially mounted on the surface of a flat wiring board.

[0002]

2. Description of the Related Art Generally, as shown in FIG. 4, a quartz vibrating element comprises a rectangular quartz plate 10 and vibrating electrodes 11 and 12 formed on both main surfaces of the quartz plate 10. In addition, electrode pads 11a, 11b, 12a, and 12b are formed on both vibrating electrodes 11 and 12 for connection to an external circuit. The electrode pad 11a is provided at one corner of the one end of the quartz substrate 10 (near the upper corner in the drawing), and the electrode pad 11b is provided at the other corner of the other end of the quartz substrate 10 (the lower corner in the drawing). (In the vicinity of the portion) and extends to the main surface on the back side of the quartz substrate 10. The electrode pad 12a is located at the other corner of the one end of the quartz substrate 10 (near the lower corner in the drawing), and the electrode pad 12b is located at the other corner of the other end of the quartz substrate 10 (the lower corner in the drawing). (In the vicinity of the corner) and extends to the front-side main surface of the quartz substrate 10. Such a crystal vibrating element 1 is bonded to a container or a wiring board and hermetically sealed.

Normally, as shown in FIG. 5, a container and a wiring board 20 to which the quartz-crystal vibrating element 1 is joined are provided with step portions 21 and 24 on which both ends of the quartz-crystal vibrating element 1 are placed. In the step portion 21, for example, a connection pad 22 connected to the electrode pad 11a of the crystal resonator element 1 was formed. The quartz vibrating element 1 is electrically connected to the surface of the step portion 21 via the conductive adhesive 23 and is mechanically joined at the same time.

However, such a bonding structure of the crystal resonator element 1 requires the steps 21 and 24 on the wiring board 20, and it is difficult to reduce the height of the whole crystal resonator. As a structure in which the step portions 21 and 24 are eliminated, a structure in which the crystal resonator element 1 is substantially horizontally arranged on the flat wiring substrate 25 as shown in FIG. No. 81137).

In the bonding structure shown in FIG. 6, an insulating adhesive 26 is applied to a part of a wiring board 25, and the insulating adhesive 2
The fixed end of the crystal vibrating element 1 is placed on 6. Next, the insulating adhesive 26 is cured, and the crystal resonator element 1 is fixed to the wiring board 25. Thereafter, the electrode pads 11a and 12a of the crystal resonator element 1 were electrically connected to the connection pads 27 formed on the wiring board 25 by using a conductive adhesive 28 and a wire bonding thin wire.

[0006]

In the structure shown in FIG. 6, when the insulating adhesive 26 is hardened to fix the fixed end of the quartz-crystal vibrating element 1, a space for lifting the free end of the quartz-crystal vibrating element 1 is formed. A jig had to be used. Therefore, the manufacturing method becomes complicated.

The insulating adhesive 26 for joining the quartz-crystal vibrating element 1 and the wiring board 25 is formed on the lower surface of the fixed end of the quartz-crystal vibrating element 1 so as to spread out in a plane. This is a structure that occurs because the insulating adhesive is applied and the crystal vibrating element is mounted as it is. In such a structure, the insulating adhesive 26 spreads to the inside of the crystal vibrating element 1 and The resonance resistance of the vibrating element 1 is greatly deteriorated.

Further, since the adhesive spread on the lower surface of the crystal vibrating element is an insulating material, the connection pad 27 cannot be formed on this portion of the wiring board 25.

Therefore, it is necessary to form the connection pad 27 in a region other than the mounting region of the crystal vibrating element 1, and the wiring board 25 becomes large.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a quartz-crystal vibrating element can be easily formed on a flat wiring board while securing a vibrating space. Is provided stably, and a crystal vibrating element for miniaturizing a wiring board is provided.

[0011]

According to the present invention, there is provided a quartz crystal in which a vibrating electrode is formed on both main surfaces of a rectangular quartz plate, and an electrode pad extending from both vibrating electrodes is formed on at least one end of the lower surface. A crystal resonator in which a vibration element is mounted on a wiring substrate having connection pads on the upper surface by bonding the electrode pads and the connection pads via a conductive resin adhesive, wherein the crystal element is mounted on the conductive adhesive. This is a crystal resonator in which a fulcrum member that supports the lower surface of the crystal resonator element is arranged on the inner side close to the crystal resonator.

Preferably, the fulcrum member has a length of one length in the longitudinal direction of the quartz oscillator from one end of the quartz oscillator.
That is, it is in contact with and supported at a position within 0 to 18%.

[0013]

According to the present invention, since the crystal resonator is arranged in a plane on the flat wiring board, a crystal resonator having a reduced height can be achieved. One end (fixed end) of the crystal unit
A conductive resin adhesive is disposed on the lower surface of the wiring board, and is electrically connected to connection pads of the wiring board. That is, the connection pad can be formed also in the mounting region of the crystal resonator. As a result, the size of the wiring board can be reduced.

The joint structure between the fixed end portion of the crystal resonator and the wiring board is formed on or near the inner side of the connection pad of the wiring board (side near the free end of the crystal resonator). A fulcrum member that contacts the lower surface of the quartz vibrating element;
A conductive resin adhesive disposed outside of the fulcrum member on the fixed end side of the crystal resonator element.

Therefore, the conductive resin adhesive spreads inside the lower surface of the crystal vibrating element even when the conductive resin adhesive is applied and the crystal vibrating element is placed on the upper surface thereof due to the presence of the support member. Nothing. Therefore, it is possible to effectively suppress the deterioration of the resonance resistance of the crystal resonator and the occurrence of damping.

Also, on the lower surface of the fixed end of the quartz vibrating element,
Since the electrode pad of the crystal resonator and the connection pad of the wiring board can be connected via the conductive resin adhesive, the connection pad can be formed in the mounting area of the crystal resonator on the wiring board, so that the connection pad of the wiring board can be formed. The size can be reduced.

Further, the quartz vibrating element and the wiring board are joined by the hardening of the conductive adhesive, but the volume shrinkage of the conductive adhesive occurs when the conductive adhesive is hardened. , A contraction stress is generated that pulls the fixed end portion toward the wiring board.

As a result, the free end side of the crystal vibrating element rises with the fulcrum member in contact with the lower surface of the crystal vibrating element as a boundary. As a result, the free end of the crystal vibrating element is lifted from the state in which the free end of the crystal vibrating element is in contact with the wiring board due to its own weight, and a special jig is required for the vibration space between the crystal vibrating element and the wiring board It can be easily formed without doing so.

The position at which the fulcrum member contacts the lower surface of the fixed end of the quartz vibrating element is defined by
When the distance in the longitudinal direction of the quartz-crystal vibrating element is within 10 to 18%, the other end of the quartz-crystal vibrating element is stably lifted to form a vibration space, and the resonance resistance of the quartz-crystal vibrating element is not deteriorated at all. .

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a crystal resonator according to the present invention will be described in detail with reference to the drawings.

FIG. 1 is an external perspective view of a crystal unit according to the present invention, and FIG. 2 is a longitudinal sectional view thereof.

In the figure, reference numeral 1 denotes a quartz vibrating element, 2 denotes a wiring board, 3 denotes a fulcrum member, and 4 denotes a conductive resin adhesive.
In the drawing, a lid for hermetically sealing the quartz vibrating element 1 is shown.
Alternatively, the sealing member is omitted.

As shown in FIG. 4, the crystal resonator 1 has vibration electrodes 11 and 12 formed on both main surfaces of a crystal substrate 10, and the vibration electrodes 11 and 12 are formed on both main surfaces at both ends. Electrode pads 11a, 12a, 11b, 12b extending from 12
Are formed.

The quartz vibrating element 1 is planarly joined to the wiring board 2 with a predetermined vibrating space on the surface of the wiring board 2. This bonding is achieved only on one end side of the crystal resonator element 1. The joined end is referred to as a “fixed end”, and the unfixed end is referred to as a “free end”.

The wiring board 2 can be exemplified by a ceramic wiring board, a glass epoxy wiring board, or the like. The surface of the wiring board 2 is, for example, a rectangular connection pad 5 electrically connected to the crystal resonator element 1.
A predetermined wiring pattern 5 including a and 5b is formed.
The wiring pattern 5 is formed of a conductor containing Ag or Cu as a main component. The wiring board 2 only needs to have a flat plate shape at least in the region where the crystal vibrating element 1 is disposed, and a frame or the like may be provided in addition to the region where the crystal vibrating element 1 is disposed.

The fulcrum member 3 is made of, for example, a polyimide resin,
A resin fulcrum member obtained by heating and curing a resin adhesive paste made of an epoxy resin, a silicone resin, or the like, a gap material-containing resin fulcrum member containing a gap material such as a glass fever in the resin paste, A conductive resin fulcrum member containing Ag particles or Cu particles in a resin paste, a thermocompression-bonded resin film, and the like can be exemplified. These fulcrum members 3 are formed on the surface of the wiring board 2 so as to have a height of about 20 to 50 μm.
It is formed near the inner side of the electrode pads 5a and 5b (side from the free end side of the crystal resonator element 1). When the fulcrum member 3 has conductivity, each electrode pad 5a, 5b
Each is formed independently. When the fulcrum member 3 is insulative, it is formed independently for each of the electrode pads 5a and 5b, or in the width direction of the wiring board 2 so as to straddle between the two electrode pads 5a and 5b. It is formed continuously.

The conductive resin adhesive 4 contains, for example, a polyimide-based resin, an epoxy-based resin, or a silicone-based resin as a main component and a conductive material such as Ag uniformly dispersed therein. The conductive resin adhesive 4 is applied on the connection pads 5 a and 5 b of the wiring board 2 and outside of the portion where the fulcrum member 3 is formed, that is, on the fixed end side of the crystal vibrating element 1 and heat-cured. Formed. The conductive resin adhesive 4 is
The wiring board 2 and the fixed end of the crystal unit 1 are mechanically joined, and at the same time, the connection pads 5a, 5b of the wiring board 2 are connected.
And the electrode pad 11 on the lower surface of the fixed end of the crystal resonator element 1
a and 12a are electrically connected to each other.

Next, a method of manufacturing the crystal resonator of the present invention will be described.

First, a wiring board 2 on which a wiring pattern 5 including a crystal resonator element 1 and connection pads 5a and 5b is formed is prepared.

Next, as shown in FIG.
To form In the example, the fulcrum member 3 is formed independently of the connection pads 5a and 5b of the wiring board 2 because the fulcrum member 3 is formed using a conductive resin paste containing Ag particles in a polyimide resin. In the figure, only the connection pad 5a side is shown.

The fulcrum member 3 is connected to the connection pad 5 of the wiring board 2.
A is formed by applying and curing the above-mentioned conductive resin paste along the side near the center of the wiring board 2 in FIG.

In the figure, the conductive resin paste was not completely cured, but was temporarily cured as the support member 3 (support member 30). Temporary curing means that the temperature is
This is a state in which a part of the solvent contained in the paste is volatilized by heat treatment for 0 to 30 minutes or standing at room temperature for 2 to 3 hours. still,
The support member 30 has a height of 20 to 50 μm and has a curved surface.

Next, as shown in FIG. 3B, a conductive resin paste 40 to be the conductive resin adhesive 4 is applied.

The conductive resin adhesive 4 is made of a conductive resin paste containing, for example, a polyimide resin as a main component and Ag particles uniformly dispersed therein. That is, the connection pads 5a, 5b
Applied on top. At this time, the applied conductive resin paste 40 does not spread to the inside of the wiring board 2 beyond the temporarily cured fulcrum member 30.

Next, as shown in FIG. 3 (c), the electrode pads 11a, 1a, 1b, 1c, 1d of the crystal vibrating element 1 are placed on the tentatively cured fulcrum member 30 and the resin paste 40 to be the conductive resin adhesive 4.
2a so that the crystal vibrating element 1
Place the fixed end of.

At this time, only the fixed end portion of the crystal resonator element 1 is placed on the fulcrum member 3 and the resin paste 40 serving as the conductive resin adhesive 4. 2 and is placed in an inclined state as a whole of the crystal resonator element 1.

Next, as shown in FIG. 3 (d), the conductive paste 4
The fulcrum member 30 and the temporarily hardened fulcrum member 30 are completely heated and hardened.
That is, the heat treatment is performed at about 200 ° C. This allows
The fulcrum member 30 in the temporarily cured state becomes the branch member 3, and the conductive paste 40 becomes the conductive resin adhesive 4.

At this time, since the fulcrum member 30 has been pre-cured, the shrinkage behavior during the heat curing is very small. On the other hand, the shrinkage behavior of the conductive resin adhesive 4 is extremely large. That is, the conductive paste 40 serving as the conductive resin adhesive 4 is made of the quartz vibrating element 1 and the wiring board 2.
At the same time, a volume shrinkage occurs while being bonded. The shrinkage stress due to the volume shrinkage is generated between the wiring board 2 and the fixed end of the crystal resonator element 1, and the wiring board 2 side is substantially fixed. Is pulled to the wiring board 2 side.

Thus, with the fulcrum member 3 located inside the fixed end of the crystal resonator element 1 as a fulcrum, the fixed end of the crystal resonator element 1 is drawn toward the wiring board 2 as shown by an arrow A in the figure. On the contrary, the applied force operates on the free end side of the crystal resonator element 1 as shown by the arrow B in the figure. As described above, by curing the conductive resin adhesive 4 at the fixed end of the crystal resonator element 1, the free end of the crystal resonator element 1 is lifted, and between the crystal resonator element 1 and the wiring board 2. Thus, a predetermined vibration space of the crystal vibrating element 1 can be formed.

Further, mechanical bonding between the crystal vibrating element 1 and the wiring board 2 and the electrode pads 11a, 1
Electrical connection between the connection pads 2a and the connection pads 5a and 5b of the wiring board 2 is achieved.

Next, although omitted, a sealing lid and a sealing resin are formed on the wiring board 2 so as to secure a vibration space around the crystal resonator element 1.

According to the present invention described above, the quartz vibrating element 1 is disposed on the flat wiring board 2 in a plane, and only a gap substantially corresponding to the height of the fulcrum member is formed therebetween. Therefore, a low-profile quartz oscillator can be achieved.

A conductive resin adhesive 4 is disposed on the lower surface of the fixed end of the crystal resonator element 1 and is electrically connected to the connection pads 5a and 5b of the wiring board 2. Therefore, since the connection pads 5a and 5b can be arranged also in the mounting area of the crystal resonator element 1, the size of the wiring board 2 can be reduced.

Even if the paste 40 which becomes the applied conductive resin adhesive 4 is applied, and the quartz vibrating element 1 is mounted on the upper surface thereof, the conductive resin adhesive 4 Since the paste 40 does not spread inside the lower surface of the crystal vibrating element 1, the resonance resistance of the crystal vibrating element 1 does not deteriorate, and the occurrence of damping can be effectively suppressed.

Further, the fixed end of the quartz-crystal vibrating element 1 is heated and cured with a paste 40 serving as the conductive resin adhesive 4, whereby the joining between the quartz-crystal vibrating element 1 and the wiring board 2 is achieved. Volume shrinkage occurs in the paste 40 which becomes
Shrinkage stress is generated at the fixed end of the crystal resonator element 1. As a result, the fixed end of the crystal vibrating element 1 is pulled toward the wiring board 2 with the fulcrum member 3 as a boundary, so that the free end of the crystal vibrating element 1 rises.

In other words, the crystal vibrating element 1 can be simply obtained by simply heating and curing the paste 40 that becomes the conductive resin adhesive 4.
A predetermined vibration space of the crystal vibrating element 1 can be formed between the substrate and the wiring board 2.

In the above embodiment, the fulcrum member 3 also uses a conductive resin adhesive, and the conductive resin adhesive 4 is in contact with the fulcrum member 3.
Even if formed on a and 5b, there is no reduction in electrical connection reliability.

Furthermore, by forming the fulcrum member 3 in a temporarily cured state and completely curing the conductive resin adhesive 4 at the same time as the heating and curing of the conductive resin adhesive 4, the compatibility between the two becomes very good.
The mechanical bonding strength, especially the bonding strength and electrical reliability in long-term use are improved.

The present inventors use a 6.0 mm × 1.6 mm strip-shaped quartz-crystal vibrating element (fundamental wave: 20 Mz) to determine the position where the fulcrum member 3 is supported on the lower surface of the quartz-crystal vibrating element 1 and the conductive resin. The state of the free end of the crystal vibrating element when the paste 40 serving as the adhesive 4 was cured was examined.

The fulcrum member 3 is made of a polyimide resin so as to have a height of 30 μm along the inner sides of the electrode pads 5 a and 5 b of the wiring board 2 and a curved end surface. A conductive resin adhesive was applied and temporarily cured to form a film.

Further, a paste 40 serving as the conductive resin adhesive 4 of the polyimide resin and the outside of the fulcrum member 3, ie,
The coating was performed mainly around the connection pads 5a and 5b, the coating amount was about 7.7 × 10 ⁻⁶ cm ³ , and the coating height was 30 μm.

The position of the vertices of the curved surface of the fulcrum member 3 (the fulcrum position) was variously changed, and the floating amount of the free end side of the crystal resonator element 1 was measured. Note that the fulcrum position is shown as a ratio (%) from the end face of the fixed end of the crystal resonator element 1 to the length of the crystal resonator element 1. As a criterion for the quality of the floating amount, a product having a variation in the floating amount but having a minimum floating amount of 0 was determined to be defective.

When the ratio of the fulcrum positions is less than 10% (less than 0.6 mm from the fixed end of the crystal vibrating element 1), the lifting amount of the free end of the crystal vibrating element 1 is distributed in the range of 0 to 30 μm. In some cases, the free end of the crystal resonator element 1 is completely in contact with the wiring board.

If the fulcrum position ratio exceeds 10%, the free end of the quartz vibrating element 1
There is no one whose free end is in contact with the wiring board.

For example, when the ratio of the fulcrum positions is 15% (less than 0.6 mm from the fixed end of the quartz vibrating element 1), the lifting amount of the free end of the quartz vibrating element 1 is 20 to 40 μm.
m. The fulcrum position ratio is 25%
(Less than 1.5 mm from the fixed end of the quartz-crystal vibrating element 1), the lifting amount of the free end of the quartz-crystal vibrating element 1 is 20
It is distributed in the range of ５０50 μm.

Therefore, it is necessary to set the fulcrum position to exceed 10% in view of the floating amount on the free end side of the crystal resonator element.

At the same time, the resonance resistance of the quartz vibrating element 1 was examined. The practical value of the resonance resistance is about 15Ω.

When the ratio of the fulcrum positions is 10%, the free end of the crystal vibrating element 1 rises from the wiring board, and the resonance resistance is as good as about 10Ω. When the fulcrum position ratio is 18%, the resonance resistance is about 15Ω.

Further, when the ratio of the fulcrum positions is 25%, the resonance resistance exceeds about 20Ω, and as a result, oscillation stops even when connected to an oscillation circuit. This is due to the fact that the fulcrum position is located closer to the center of the quartz-crystal vibrating element, which hinders stable oscillation of the quartz-crystal vibrating element.

As described above, the fulcrum position is one point from the fixed end with respect to the longitudinal dimension of the crystal vibrating element, in which the free end of the crystal vibrating element 1 completely rises from the wiring board 2.
In order to keep the resonance resistance above 0% and the resonance resistance does not exceed a practical value, it is important to set it within 18% from the fixed end.

In the above embodiment, the fulcrum member 3 is arranged on the wiring board 2 side, but may be arranged on the quartz oscillator 1 side. For example, a plate member made of a metal material such as phosphor bronze is bonded to the inner side of the electrode pads 11 a and 12 a on the lower surface side of the crystal resonator element 1, and this plate member is used as the support member 3. Then, the crystal vibrating element 1 to which the support member 3 is joined may be joined onto the wiring board 2 via the conductive adhesive 4.

In the above embodiment, the description has been made using the flat wiring board 2. However, at least the region where the crystal vibrating element 1 is mounted is in a flat state, and the wiring substrate is surrounded so as to surround the mounting area of the crystal vibrating element. A frame may be provided around 2. This frame attaches a lid that hermetically seals the quartz vibrating element.

The quartz vibrating element 1 is
Although the electrode pads are formed on the fixed end portion and the free end portion, respectively, in order to eliminate the directionality, it is sufficient that the electrode pads are formed only on at least the fixed end portion.

When a band-shaped film or a flat plate member having a certain width is used as the fulcrum member 3, the fulcrum position is located on the inner side of the crystal vibrating element 1 (free of the crystal vibrating element 1) in view of the resonance resistance. (End side).

Although the conductive resin adhesive 4 is disposed on the lower surface of the fixed end of the quartz-crystal vibrating element 1, it may be arranged on the upper surface of the fixed end of the quartz-crystal vibrating element 1. Good. In this case, not only the electrical connection reliability, but also the bonding strength between the crystal vibrating element 1 and the wiring board 2 is improved, and the load on the fixed end side of the crystal vibrating element 1 is increased, and the floating on the free end side is lifted. Is relatively easy.

The wiring pattern 5 of the flat wiring board 2
Alternatively, electronic components such as an oscillation IC, a resistor, and a capacitor may be mounted.

[0067]

As described above, since the quartz-crystal vibrating element is planarly joined to the flat wiring board, the overall height of the quartz-crystal vibrator can be reduced.

The bonding between the crystal resonator and the wiring board is achieved only at the fixed end of the crystal resonator via a conductive adhesive. In addition, the fulcrum member is disposed inside the conductive adhesive (on the free end side of the crystal vibrating element) on the lower surface on the fixed end side of the crystal vibrating element.

As a result, the connection pads can be arranged in the mounting area of the crystal vibrating element of the wiring board, so that the degree of freedom of the wiring pattern on the wiring board is improved.
The size of the wiring board can be reduced.

Further, since the paste serving as the conductive resin adhesive is unlikely to spread on the inner side of the lower surface of the crystal vibrating element due to the fulcrum member, the resonance resistance of the crystal vibrating element does not deteriorate and the characteristics of the crystal vibrator are stabilized.

The free end of the crystal vibrating element, which is inclined and mounted on the wiring board, is raised by the shrinkage stress of the conductive resin adhesive during curing and the fulcrum member supporting the lower surface of the crystal vibrating element. Since the bonding is performed, the crystal resonator can easily form a vibration space between the wiring substrate and the crystal resonator element.

[Brief description of the drawings]

FIG. 1 is an external perspective view of a crystal unit according to the present invention.

FIG. 2 is a longitudinal sectional view of the crystal unit of the present invention.

FIGS. 3A to 3D are schematic views illustrating the steps of manufacturing the crystal resonator of the present invention.

FIG. 4 is a plan view of the crystal resonator element.

FIG. 5 is a cross-sectional view of a conventional crystal unit without a lid.

FIG. 6 is a cross-sectional view of another crystal unit without a conventional lid.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Crystal oscillator 2 ... Wiring board 3 ... Support member 4 ... Conductive resin adhesive 5 ... Wiring pattern 5a, 5b ... Connection pad 11a, 12a , 11b, 12b ... electrode pad

Claims (2)

[Claims] 1. A quartz-crystal vibrating element in which vibrating electrodes are formed on both main surfaces of a strip-shaped quartz plate and electrode pads extending from both vibrating electrodes are formed on at least one end of the lower surface, and connection pads are provided on the upper surface. A quartz resonator mounted on a wiring board by bonding the electrode pad and the connection pad via a conductive resin adhesive, wherein a quartz vibrating element is provided on an inner side close to the conductive adhesive. A fulcrum member for supporting a lower surface of the crystal resonator. 2. The fulcrum member has a length in the longitudinal direction of 10 to 18 from one end of the quartz vibrating element.
2. The crystal unit according to claim 1, wherein the crystal unit is supported in contact with the position in the range of%.