JPH0539030U - Piezoelectric vibrator - Google Patents

Abstract

(57) [Summary] [Object] To provide a sealing portion structure in which the size of the outer diameter of a piezoelectric vibrator container is not increased by forming a sealing film for maintaining the degree of vacuum inside the piezoelectric vibrator container. [Structure] A sealing film 6 is provided only on an outer peripheral portion of a fixing portion 3 between a supporting member 2 supporting a piezoelectric material 5 and a lid 1. [Effect] Since the sealing film is formed only on the fixed portion of the support member and the lid and not on the portion that is not necessary for maintaining the degree of vacuum in the piezoelectric vibrator container, the outer diameter of the piezoelectric vibrator increases. It is possible to reduce the thickness and size of the piezoelectric vibrator without doing so. Furthermore, since the waste of the sealing film material can be omitted, the cost can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a structure of a piezoelectric vibrator necessary for housing a piezoelectric material in a vacuum or an atmosphere of an inert gas.

[0002]

[Prior Art]

 Conventionally, as a method for sealing a piezoelectric vibrator container that houses a crystal vibrating piece, a method of press-fitting with a solder interposed in a gap between a support member that supports and fixes a piezoelectric material and a lid, and a support member and a lid are used. There is a method of resistance welding, a method of cold pressure welding with oxygen-free copper interposed in the gap between the support member and the lid, and a method of joining the support member and the lid with a low melting point glass.

In recent years, when considering surface mounting by an automatic inserter, which is widely used, electronic parts are made lighter, thinner, smaller and easier, and easy to insert automatically, and in order to pass through a reflow furnace, for example, solder during reflow is melted. It is necessary to withstand the temperature of 260 ° C for 30 seconds. For this reason, the piezoelectric vibrator is required to be thin, small, and have high heat resistance, but the above method cannot satisfy the requirements described below.

A method of press-fitting with a solder interposed in a gap between a support member that supports and fixes a piezoelectric material and a lid can be downsized, but since solder, which is a low-melting metal, intervenes, heat resistance is low. It causes inconvenience.

On the other hand, in the method of resistance welding the support member and the lid, and the method of cold pressure welding with oxygen-free copper interposed in the gap between the support member and the lid, there is no problem in heat resistance, but there is no problem with the support member. The lid requires a flange for resistance welding and cold pressure welding, which makes it difficult to make it thinner and smaller.

In addition, in the method of joining the support member and the lid with the low melting point glass, the melting temperature of the low melting point glass is as high as around 450 ° C., so that the gas emitted from the joining material of the piezoelectric material and the support member. As a result, the gas pressure inside the piezoelectric vibrator container increases. Furthermore, there is a problem that the released gas causes deterioration of the electrode material formed on the piezoelectric material, which deteriorates the characteristics of the piezoelectric vibrator.

Therefore, in order to achieve thinning, miniaturization and high heat resistance of the piezoelectric vibrator, there is a configuration as shown in FIG.

In this method, as shown in FIG. 3, first, the lid 1 is inserted and fixed to the support member 2 that supports the piezoelectric material 5 by using the bonding material 7, and the lid 1 is arranged in the vacuum device. At this time, since the low melting point metal such as solder is not formed on the support member 2 and the lid 1, the piezoelectric vibrator container 4 is not hermetically sealed.

Therefore, when the vacuum device is evacuated, the gas inside the piezoelectric vibrator container 4 passes through the gap of the fixing portion 3 between the support member 2 and the lid 1, and the gas of the piezoelectric vibrator container 4 moves. Since it goes out, the inside of the piezoelectric vibrator container 4 has the same degree of vacuum as the inside of the vacuum device.

Thereafter, for example, nickel is formed as a thin film or thick film sealing film 6 on the outer peripheral portions of the support member 2 and the lid 1 by a vacuum deposition method. As a result, the sealing film 6 blocks the passage of gas in the gap between the support member 2 and the lid 1, and the support member 2 and the lid 1 can be sealed. Is maintained.

FIG. 3 shows a conventional example in which the supporting member 2 and the lid 1 are cylindrical, but this method is also applicable to the flat type container 8 as shown in FIG. Applicable.

As shown in FIG. 4, the flat container 8 is composed of a support member 2 that supports the piezoelectric material 5 using a bonding material 7 and a lid 1, and the sealing film 6 is a flat member of this flat container 8. It is formed to cover the entire top surface.

[0013]

[Problems to be solved by the device]

 In the structure shown in FIGS. 3 and 4, the sealing film for blocking the passage of air in the gap between the supporting member and the lid of the piezoelectric vibrator is provided on the surface of the piezoelectric vibrator container or the flat container. It covers most areas. However, if the entire surface of the container is covered with the sealing film, the outer diameter of the container increases, which hinders reduction in thickness and size.

An object of the present invention is to solve the above problems and provide a sealing structure for a piezoelectric vibrator, which can be easily thinned and downsized.

[0015]

[Means for Solving the Problems]

 In order to achieve the above object, in the structure of the piezoelectric vibrator of the present invention, a lid is inserted into a supporting member that supports the piezoelectric material, and a sealing film is formed on the outer periphery of the supporting member and the lid to form a piezoelectric resonator container. In the piezoelectric vibrator to be sealed, the support member and the lid are provided with a sealing film only on the outer peripheral portion of the fixing portion.

[0016]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the structure of the piezoelectric vibrator according to the present invention.

As shown in FIG. 1, the piezoelectric vibrator container 4 is composed of a support member 2 for supporting the piezoelectric material 5 using a bonding material 7 and a lid 1.

The piezoelectric vibrator container 4 in which the lid 1 is inserted and fixed to the support member 2 is arranged in a vacuum device (not shown) to perform vacuuming. After that, a sealing film 6 such as a single metal film, an alloy film, a nitride film, an oxide film, a diamond-like carbon film is formed to block the gas passage between the support member 2 and the lid 1. , Maintain the degree of vacancy inside the piezoelectric vibrator container 4.

At this time, the sealing film 6 is formed only on the outer peripheral portion of the fixing portion 3 between the supporting member 2 and the lid 1, and is formed on a portion which is not necessary for maintaining the degree of vacuum in the piezoelectric vibrator container 4. do not do.

Therefore, waste of the material of the sealing film 6 can be saved, leading to a reduction in cost. This effect is particularly great when an expensive material such as gold (Au) is used as the sealing film 6.

Further, since the entire surface of the piezoelectric vibrator container 4 is not covered with the sealing film 6, the outer diameter of the piezoelectric vibrator does not increase, and the piezoelectric vibrator can be made thinner and smaller. ..

As a method of forming the sealing film 6 only on the outer peripheral portion of the fixing portion 3 between the supporting member 2 and the lid 1, there are the following methods.

A mask is formed to cover portions other than the outer peripheral portion of the fixed portion 3, and the sealing film 6 is formed by means such as a vacuum vapor deposition method, a sputtering method, a plasma CVD method, an ion plating method.

Alternatively, without using a mask, ultrafine particles that are the material of the sealing film 6 are conveyed in a mixed state together with a gas, and a gas vapor deposition method capable of locally forming a film by jetting at high speed from a nozzle is used for sealing. The film 6 is formed.

Although FIG. 1 shows the case of a tuning fork type crystal as the piezoelectric material 5, the piezoelectric material 5 may be another crystal piece such as an AT plate or a piezoelectric material other than crystal without any problem. ..

Further, although FIG. 1 shows the case where the supporting member 2 and the lid 1 are cylindrical, the flat type container 8 as shown in FIG. 2 has the supporting member 2 and the lid 1 similarly to FIG. By forming the sealing film 6 only on the fixing portion, the same effect as the structure described with reference to FIG. 1 can be obtained.

FIG. 2A is a sectional view showing the flat type container, and FIG. 2B is a plan view showing the flat type container.

The flat type container 8 in FIG. 2 is composed of a supporting member 2 that supports the piezoelectric material 5 using a bonding material 7 and a lid 1, and a sealing film 6 fixes the supporting member 2 and the lid 1 to each other. Provide only on the outer periphery of the section.

When the support member 2 is provided with the electrode 9 for the external connection electrode, an insulating film is used as the sealing film 6.

Note that the sealing film may be formed by using a thermal spraying method in the sealing in an inert gas atmosphere instead of the sealing in vacuum.

[0031]

[Effect of the device]

 As described above, according to the present invention, the lid is inserted into the support member that supports the piezoelectric material, and the sealing film is formed on the outer peripheral portion of the support member and the lid to seal the piezoelectric vibrator container. In the piezoelectric vibrator to be stopped, the sealing film is formed only on the outer peripheral part of the fixed part of the support member and the lid, and is not formed on the part that is not necessary to maintain the degree of vacuum in the piezoelectric vibrator container. Therefore, it is possible to prevent an increase in the outer diameter of the piezoelectric vibrator container. Furthermore, since the waste of the material for the sealing film is omitted, the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a piezoelectric vibrator according to the present invention.

FIG. 2 is a view showing a structure of a piezoelectric vibrator according to another embodiment of the present invention.

FIG. 3 is a sectional view showing a structure of a piezoelectric vibrator in a conventional example.

FIG. 4 is a drawing showing a structure of a piezoelectric vibrator in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lid 2 Supporting member 3 Fixed part 4 Piezoelectric vibrator container 5 Piezoelectric material 6 Sealing film 7 Bonding material 8 Flat type container

Claims (1)

[Scope of utility model registration request] 1. A piezoelectric vibrator in which a lid is inserted into a support member that supports a piezoelectric material, and a sealing film is formed on an outer peripheral portion of the support member and the lid to seal a piezoelectric vibrator container. A piezoelectric vibrator, wherein the sealing film is provided only on an outer peripheral portion of a fixing portion between the lid and the lid.