JPH06152308A - Piezo-electric element container and its sealing method - Google Patents

Abstract

PURPOSE:To extremely quickly complete welding and to obtain an inexpensive and compact product with reduced manhour by allowing a current to flow between specific lower and upper electrodes to execute welding. CONSTITUTION:Since the width size of a metallic frame 3 of a container 1 is larger than that of a can 7, the frame 3 projects from the periphery of the can 7 when the can 7 set up on the container 1 is observed from its upper part. On the other hand, the upper electrode 11 is set up on the upper part of a flange part 8 of the can 7, and while pressing the electrode 11, a current is allowed to flow between the upper and lower electrodes 11, 10. Thereby the frame 3 and the can 7 are mutually welded and the can 7 is sealed. Since the lower electrode 10 can easily come into contact with the frame 3, the upper electrode 11 is brought into contact with the can 7 from the upper part of the flange part 8 and a current is allowed to flow while pressing the upper electrode 11, welding can be instantaneously executed differently from convensional seam welding, sealing manhour can be reduced and a cost-reduce product can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container structure such as a piezoelectric vibrator, a surface acoustic wave filter and a piezoelectric oscillator, and a method for sealing the container.

[0002]

2. Description of the Related Art Conventionally, a container containing a piezoelectric element such as a piezoelectric vibrator, a surface acoustic wave filter, a piezoelectric oscillator, etc. is usually constructed so as to be shielded from the outside by resistance welding, cold pressure welding or the like. This is because when the piezoelectric element receives moisture or oxygen from the outside,
This is because there is a possibility that the frequency may change due to oxidation of the electrodes. In resistance welding, when the base side, that is, the container that fixes the piezoelectric element is made of metal, flange parts are provided on the can side and the base side, which are lids, and the flange parts are sandwiched between the electrodes from above and below, and a current is applied to weld. Was.
When the container becomes thinner and the base that contains the piezoelectric element is made of insulating material such as ceramic or glass, a metal material is applied on the insulating material and the current is applied while pressing the edge of the can with a roller from above the can. The so-called seam welding was performed.

[0003]

However, seam welding is
Since the rollers are welded around the cans one by one,
There is a drawback that it takes time to weld one piece. Therefore, there has been a demand for a method capable of welding in a short time without requiring a welding man-hour.

[0004]

1 is a sectional view showing the structure of a container according to the present invention. In this example, a surface acoustic wave filter is mounted, and the container 1 has a metal frame 3 fixed on an insulating substrate 2. A conductor 4 such as silver-palladium is applied to the surface of the insulating substrate and baked to form an extraction electrode, which is led out from the inside to the bottom surface of the container.
A wire 6 is connected to the conductor 4 from the surface acoustic wave filter 5. The can 7 serving as a lid is made of metal, and the flange portion 8 is provided with a projection 9. The container 1 and the can 7 are smaller than the container by 0.1 to 0.4 mm, and are dimensioned so that the container-side electrode for welding can contact them. The feature of this container is that the depth of the can can be deeper than that of the conventional seam welding. In seam welding, the roller angle is 5
Since it is a small angle of -10 degrees, the height (depth) of the can causes the roller to be caught. So I had to use an almost flat lid.

However, in the present invention, welding can be performed instantaneously by using the electrode shown in FIG. Welding can be done in a fraction of the same time as a resistance welded container with a flange. FIG. 2 is a cross-sectional view showing the sealing method of the present invention. Since the width dimension of the metal frame 3 of the container 1 is larger than the width dimension of the can 7, the metal frame 3 protrudes around the can when the can 7 is placed and viewed from above. The lower electrode 10 is brought into contact with the entire circumference of this portion. In the figure, the lower electrode 10 is shown separately on the left and right, but it is integrated. On the other hand, the upper electrode 11 is applied from above the flange portion of the can and pressure is applied to pass an electric current between the upper electrode and the lower electrode. As a result, the metal frame and the can are welded and sealed. In the present invention, the container has a structure in which the metal frame has a size larger than that of the can, and has a structure in which the metal frame is sufficiently projected. This is to make it easier for the lower electrode to contact the metal frame. As a sealing method, the lower electrode is brought into contact with the entire circumference of the metal frame.
In addition, the upper electrode comes into contact with the flange portion of the can, and current is applied while welding to apply welding. In this way, unlike conventional seam welding, welding can be performed in one shot, so a sealing man-hour is not required and a low-cost product can be obtained. Further, in the case of seam welding using a roller-type electrode, if the depth of the lid is deep, it cannot be welded because it comes into contact with the roller. However, in the present invention, there is no possibility of contacting the electrode even if the depth of the lid is present. The depth of the container may be shallower than before. Conventionally, it has been necessary to design a large container so that the jig for wire bonding does not hit the container when the recess of the container is deep. However, in the present invention, since the depth can be secured in the lid, the recessed portion of the container can be made shallow, and it is not necessary to give a margin to the size of the container, which can contribute to downsizing of the container. In the present embodiment, the surface acoustic wave filter is used as an example of the piezoelectric element, but the piezoelectric element may be used together with a crystal oscillator, a crystal filter, a ceramic filter, or an IC. Although the pad type in which the conductor is applied to the insulating substrate and baked is given as the output terminal, the lead terminal may be used as the output terminal to form the J lead or the L lead.

[0006]

According to the present invention, since a lid (can) having a height higher than that of the conventional one can be used, even if the depth of the container is shallow, there is no possibility that the wire for wire bonding will come into contact with the lid. Further, even in the manufacturing method using this container, welding can be completed instantly in a remarkably short time as compared with the conventional seam welding, so that it has become possible to provide an inexpensive product with less man-hours. It was possible to contribute to further miniaturization.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a container of the present invention.

FIG. 2 is a sectional view of a container showing a sealing method of the present invention.

[Explanation of symbols]

 1 Container 2 Insulating Substrate 3 Metal Frame 5 Piezoelectric Element 7 Lid 8 Flange 10 Lower Electrode 11 Upper Electrode

Claims (2)

[Claims] 1. A piezoelectric element container in which a piezoelectric element is placed and fixed on an insulating substrate, a metal frame is arranged on the periphery of the insulating substrate, and the size of the metal frame is larger than the size of the lid. 2. A piezoelectric element is mounted and fixed on an insulating substrate, and a current is caused to flow between the lower electrode which is in contact with the peripheral portion of the metal frame and the flange portion of the lid and the upper electrode which are in contact with each other. A method for sealing a piezoelectric element container, which comprises performing welding by welding.