JPH08162890A - Vibrator - Google Patents

Abstract

PURPOSE: To enhance the air-tightness in a throughhole by connecting a conductor provided in an inner face of a throughhole of a cover to an external electrode and supplying solder in the throughhole of the cover. CONSTITUTION: A throughhole 17 made to a cover 3 is formed to be conical in which the diameter of the throughhole toward a vibrator 1 is smaller and a conductor 18 in the throughhole 17 made to the cover 3 is connected to each of external electrodes 4, 5. The upper part of the conductor 18 seals a smaller diametrical part of the upper part of the throughhole 17. Furthermore, the lower part of the conductor 18 is spread toward an open ridge of the throughhole 17 at a face of the cover 3 opposite to the vibrator 1. In this state, molten solder is flowed into the throughhole 17 to cover the conductor 18 covering the upper small diametrical part of the throughhole 17 and solidified into solder 22. Since the outer face side of the throughhole 17 is covered by the solder 22 in addition to the conductor 18, the air-tightness is enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crystal oscillator or the like.

[0002]

2. Description of the Related Art A conventional vibrator of this type includes a diaphragm and first and second covers that cover the front and back surfaces of the diaphragm and sandwich the outer peripheral portion of the diaphragm between the outer peripheral portions. The vibrating plate has a tongue-like vibrating portion inside the sandwiching portion by the first and second covers, and excitation electrodes are formed on the front and back surfaces of the vibrating portion.

Conventionally, the lead electrodes of the excitation electrodes on the front and back of the vibrating portion and the first and second external electrodes outside the first or second cover are connected to each other by the first or second cover. This is done through a conductor provided in the through hole.

[0004]

In the above-mentioned conventional example, the first,
Alternatively, since the through hole provided in the second cover is sealed only by the conductor, there is a problem that the airtightness is low.

Therefore, the present invention is intended to enhance the airtightness in the through hole portion.

[0006]

In order to achieve this object, the present invention provides a vibrating plate, a front surface and a back surface of the vibrating plate which are covered with the outer peripheral portion of the vibrating plate. First and second covers and the first or second of these
An outer electrode provided on the side opposite to at least one of the diaphragms of the cover, the diaphragm having a tongue-like vibrating section inside the sandwiching section by the first and second covers. Excitation electrodes are formed on the front and back surfaces of the vibrating section, and lead electrodes are drawn out from the front and back excitation electrodes via the root of the vibrating section. The first connecting portion is formed, the other lead electrode penetrates to the one lead electrode side, and then forms the second connecting portion, and these first and second connecting portions are the first or the second connecting portion. The second cover is electrically connected to the first and second external electrodes through the conductors provided on the inner surface of the through hole of the cover, and the solder is caused to flow into the through hole of the cover into the through hole of the solder on the external electrode side. Is the inflow of the external electrode.

[0007]

With the above structure, not only the conductor but also the outer surface side of the through hole of the first or second cover is covered with solder, so that the airtightness is improved.

Further, in this case, since a part of the external electrode is made to flow into the outer surface side of the through hole on the solder, the external electrode also becomes a part of the sealing body, so that the airtightness is further enhanced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, reference numeral 1 is a vibrating plate having a plate thickness of 100 μm.
It is composed of a crystal plate. On the front and back of the diaphragm 1,
The covers 2 and 3 made of a crystal plate having a plate thickness of 400 μm are directly joined. It is to be noted that reference numerals 4 and 5 in FIG. 1 are external electrodes and are arranged on a diagonal portion of the back surface of the cover 3. As shown in FIGS. 2 and 3, the vibrating plate 1 has a U-shaped cut groove 6 formed inward thereof, thereby forming a tongue-shaped vibrating portion 7. Excitation electrodes 8 and 9 are formed on the front surface and the back surface of the vibrating portion 7, and the base portion 1 of the vibrating portion 7 is formed.
The lead electrodes 11 and 12 are led out through 0. As shown in FIGS. 2 to 5, the end portion of the inner lead electrode 11 penetrates the diaphragm 1 by a through hole 13,
Thereafter, as shown in FIG. 3, the connecting portion 14 is formed by passing through the side of the vibrating portion 7 and extending to the opposite side of the root portion 10.
Further, the lead electrode 12 has the connection portion 1 on the side of the root portion 10.
5 is formed. Then, they are connected to the external electrodes 4 and 5, respectively, via the conductors 18 in the through holes 16 and 17 formed in the cover 3 corresponding to these connecting portions 14 and 15, respectively. The covers 2 and 3 sandwich the front and back outer peripheral portions of the diaphragm 1 at their outer peripheral portions and are directly joined to each other. That is, the portion where the lead electrode 11 passes through the side of the vibrating portion 7 is joined to the cover 3 on the outside thereof. And thus, the diaphragm 1
On the back surface side of the
5 and 6, in order to form the vibration plate 1, the vibration plate 1 is thickened only at the sandwiching part with the covers 2 and 3 to form the vibration part 7 and the lead electrodes 11 and 12. The plate thickness of the portion and the like is reduced by etching. FIG. 4 clearly shows the diaphragm 1 after this etching step, in which the back surface portion corresponding to the frame line 19 is thinned by etching. In addition, this frame line 1
The outer peripheral portion of 9 is a portion that is sandwiched and joined by the covers 2 and 3. As is clear from FIG. 4, the sandwiching width 20 on the longitudinal side of the diaphragm 1 is wider than the sandwiching width 21 on the short side. are doing.

Since the lead electrode 11 is provided on the side of the vibrating portion 7 as shown in FIG.
Are displaced from the center of the diaphragm 1 to one side.

The notch of the cut groove 6 in the root portion 10 has a semicircular shape as shown in FIG. 4, whereby cracks are less likely to occur even when an excessive impact is applied.

Now, the characteristic part of this embodiment will be described. That is, in this embodiment, as shown in FIGS. 5 and 6, the through holes 16 and 17 provided in the cover 3 have a conical shape with a smaller diameter on the diaphragm 1 side. Alternatively, copper and gold are deposited by vapor deposition or sputtering to form the conductor 18.

At this time, chromium is deposited by several hundred angstroms in order to strengthen the adhesive force between quartz and copper, and copper is deposited by several thousand angstroms to several μm. In some cases, gold is deposited in the range of hundreds to thousands of angstroms in order to prevent the oxidation of copper in the manufacturing process.

Above the conductor 18, the through holes 16 and 17 are provided.
The small diameter upper part of the
The conductor 18 is electrically connected to the bottom of the through hole 16 and 17, and the lower side of the conductor 18 extends to the opening edges of the through holes 16 and 17 on the side surface of the cover 3 opposite to the diaphragm 1.

In this state, the through holes 16 and 17 are formed so as to cover the conductor 18 portion which covers the upper small diameter portions of the through holes 16 and 17.
The solder in a fluidized state is flowed into 17 (at this time, the cover 3 is positioned upside out of FIGS. 5 and 6) and becomes the solder 22. At this time, the solder 22 is formed by a method such as printing or pouring a solder paste or a molten solder alloy. The solder 22 has a composition of eutectic solder or high-temperature solder having a melting point of 260 ° C. or higher.

The solder 22 is located in the through holes 16 and 17 as shown in FIGS.

Therefore, if the external electrodes 4 and 5 are formed by screen printing in this state, the through holes 16 and 17 are formed.
As shown in FIG. 1, FIG. 5 and FIG.
It will fall slightly within 7.

Further, as shown in FIG. 7, when the shape of the hole on the side of the small diameter of the through hole 17 is deformed, the portion 14 where the conductor 18 is connected to the lead electrode 11 is also formed along the deformation. However, the solder 22 also flows along the deformed through holes 17, and the solder 22 is also formed in an extremely dense state, which is sufficient to ensure the airtightness. In order for the solder 22 to sufficiently flow in, it is necessary to preheat the solder paste and the through-hole portion 17 to a temperature of about 50 ° C. to 80 ° C., and to make the solder 22 in a liquid state and inject it.

[0019]

As described above, according to the present invention, the diaphragm, and the first and second covers for covering the front and back surfaces of the diaphragm and sandwiching the outer periphery of the diaphragm with the outer periphery thereof, At least one of the first cover and the second cover is provided with an external electrode provided on a side opposite to the diaphragm, and the diaphragm is tongue-shaped inside the sandwiching portion by the first and second covers. The excitation electrodes are formed on the front and back surfaces of the vibration portion, and the lead electrodes are drawn from the excitation electrodes on the front and back surfaces through the root of the vibration portion. , One of the back lead electrodes forms a first connection,
The other lead electrode, after penetrating to the one lead electrode side, forms a second connection portion, and these first and second connection portions are provided on the inner surface of the through hole of the first or second cover. Through the conductors to establish electrical continuity with the first and second external electrodes, respectively, to allow the solder to flow into the through hole of the cover, and to cause the external electrode to flow into the through hole of the solder on the external electrode side. It is a thing.

With the above structure, not only the conductor but also the outer surface of the through hole of the first or second cover is covered with solder, so that the airtightness is improved.

Further, since the conductor surface is made of copper or gold, the adhesive force with solder is sufficiently strong. Further, by preheating, the solder becomes liquid and easily flows into the through hole, is reliably formed in the through hole, and the airtightness is enhanced.

[Brief description of drawings]

FIG. 1 is a perspective view of one embodiment of the present invention.

FIG. 2 is an exploded perspective view for explaining the surface state of the diaphragm of FIG.

FIG. 3 is an exploded perspective view for explaining a back surface state of the diaphragm of FIG.

FIG. 4 is a top view of the diaphragm.

5 is a cross-sectional view taken along the line AA of the vibrator in which the covers 2 and 3 are joined to the diaphragm of FIG.

6 is a cross-sectional view taken along the line BB of the vibrator in which the covers 2 and 3 are joined to the diaphragm of FIG.

FIG. 7 is an enlarged cross-sectional view of a main part of another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vibration plate 2 Cover 3 Cover 4 External electrode 5 External electrode 7 Vibration part 9 Excitation electrode 10 Root part 11 Lead electrode 12 Lead electrode 14 Connection part 15 Connection part 16 Through hole 17 Through hole 18 Conductor 22 Solder

Claims (8)

[Claims] 1. A vibrating plate, first and second covers for covering the front and back surfaces of the vibrating plate, and sandwiching the outer peripheral part of the vibrating plate with its outer peripheral part, and the first or second of these. The first and second external electrodes provided on the opposite side of at least one of the diaphragms of the cover, the diaphragm vibrating like a tongue inwardly of the sandwiching portion by the first and second covers. Has a part, and the electrodes for excitation are formed on the front and back surfaces of this vibrating part,
From these excitation electrodes on the front and back surfaces, lead electrodes are drawn out via the roots of the vibrating portions, respectively, one of these front and back lead electrodes forms the first connection portion, and the other lead electrode is After penetrating to the one lead electrode side, a second connecting portion is formed, and these first and second connecting portions are respectively provided through conductors provided on the inner surface of the through hole of the first or second cover. A vibrator in which the first and second external electrodes are electrically connected to each other, solder is allowed to flow into the through hole of the cover, and the external electrode is allowed to flow into the through hole on the external electrode side of the solder. 2. The vibrator according to claim 1, wherein Cu is formed by using a conductor provided on the inner surface of the through hole as a base of Cr. 3. The conductor provided on the inner surface of the through hole is C on Cr.
The vibrator according to claim 1, wherein u and Au are formed in this order. 4. The vibrator according to claim 1, wherein the solder to be introduced onto the conductor provided on the inner surface of the through hole is formed of a solder paste. 5. The vibrator according to claim 1, wherein the solder introduced into the conductor provided on the inner surface of the through hole is formed of a molten solder alloy. 6. The vibrator according to claim 1, wherein the solder introduced into the through hole is eutectic solder. 7. The melting point of the solder introduced into the through hole is 2
The vibrator according to claim 1, which is a high-temperature solder having a temperature of 60 ° C or higher. 8. The vibrator according to claim 1, wherein the external electrode formed on the solder which has flowed into the through hole is printed with Cu paste.