JPH0242749A - Sealing method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for sealing a vacuum-tight container for an electronic component such as a crystal resonator that requires vacuum sealing.

BACKGROUND OF THE INVENTION With the recent miniaturization, high performance, and improvement in electronic components, the number of devices that require or are effective for vacuum sealing is increasing.

In the following, a crystal resonator will be explained as an example of the prior art.

In recent years, crystal oscillators have been used in almost all electrical products such as VTR1 watches, communication devices, and telephones. Figure 1 shows a conventional crystal oscillator, the oscillator's horizontal structure, and the crystal plate 2.
Shows an enlarged view of the surrounding area. 1 is a beam wire, 2 is a crystal, a plate,
3 is a case, 4 is an upper lid, 5 is a conductive adhesive, and 8 is an anti-adhesive portion made of sealing glass. The sealing glass is generally made into a paste with a solvent and a binder. 7 is the fist swing, electric, which is deposited on the front and back of 2.
It shows the pole.

Problems to be Solved by the Invention Quartz crystal resonators made horizontally in the conventional manner often have a large change in frequency (ΔF), and this type of crystal resonator is particularly suitable for high-frequency crystals. Vibrator (e.g. 20
MHz, 30. This was noticeable in MHz vibrations (oscillators), and ΔF often deviated from ±20 ppm. Although the cause of this is not clear, it is thought that volatile substances 5 and 6 adhere to the crystal plate 2 or that stress is applied to the crystal plate 2.

Therefore, it is thought that the above problem can be solved if the vibration and number can be adjusted properly after sealing. That is, a transparent, bright glass 4 coated with a metal coating film on the inside is used as the upper lid, and after the lid is sealed, the metal coating film is evaporated by a laser through the 4 to perform vibration and fine adjustment of the number. To do this, it is necessary to keep the inside of the case in a vacuum state of 10-' Torr or less, but conventional sealing in a vacuum creates a large number of bubbles in the sealed portion 6, resulting in incomplete sealing. was often the case. This is due to the air contained in the sealing glass and binder coming out due to the vacuum condition.

Means for Solving the Problems In the present invention, after the case and the top lid are sealed with sealing glass, a glass fiber whose working temperature is lower than that of the sealing glass is inserted into the exhaust hole, and then the process is carried out in a vacuum. The above-mentioned problem is attempted to be solved by creating a vacuum inside, heating the glass fiber to its working temperature, and closing the hole.

Here, the hole is provided in a sealed portion made of sealing glass, the case, or the top cover.

Function: According to the sealing method of the present invention, the inner part is maintained at a high degree of vacuum, and as a result, a crystal resonator capable of vibration, vibration, and number adjustment is obtained after sealing.

Examples (Example 1) FIG. 1 shows an example in which a hole for inserting a glass fiber is provided in a sealed portion made of sealing glass. In FIG. 1, the lead wire and the inner part are omitted for simplicity. 1 is 4261 alloy, 3 is alumina case, 4 is borosilicate glass, 5 is silicon-based conductive paste, 6 is sealing glass 100 with a manufacturing temperature of 4.30℃
8 is a glass fiber whose working temperature is 4.10°C. 9 is a hole into which 8 is inserted.

Here, for 4, 6, and 8, those whose thermal expansion coefficients were close to 3 were used. For example, the combination of sealing glass 6 and glass fiber 8 is LS-2,001,B (thermal expansion coefficient B7.5 ,5X 10-?/”C
, 350℃) (manufactured by Nippon Electric Glass Co., Ltd.), T15
0 (G9X 10-7/”C, 382℃) and 7.1.8
, 7 (, G 8 X 10-7/”C, 342°C)
(manufactured by Iwaki Glass Co., Ltd.), and silicate glass 4 is HD-85 (thermal expansion coefficient, 65.5X 1.0-"/"
C) (manufactured by Nippon Electric Glass Co., Ltd.) was used.

First, silver was vapor-deposited on the crystal plate 2 as an electrode for excitation I vibration, and this was fixed to 1 using 5. Put these in 3 and 9
Apply 6 to the edges of 3, excluding the area where the
Temporarily glued. These and the circumference except for the part where 9 is provided,
6 was applied around the glass fiber and 4 temporarily bonded with 42.0:C, and the glass fiber 8 was sealed at 4.3° C., leaving a hole slightly larger than the diameter of the glass fiber 8 in the sealed portion. At this time, no bubbles or the like were observed in the sealed portion. Here, the shape of the glass fiber 8 is preferably a cone, a square, or a pyramid rather than a cylinder, and its length is preferably equal to the depth of the sealed portion. Further, the shape of the hole does not necessarily have to be a perfect circle. 8 was lightly inserted into 9, and then these were placed in a vacuum heating furnace, and the vacuum was evacuated to a degree of vacuum of 1 G-'Torr. Here, the air in the two parts inside the case was exhausted through the gap between the hole and the glass fiber. 410 further left in vacuum
The hole was sealed by heating to ℃ to soften the glass fiber. At this time, no loosening of the sealed portion 6 was observed. When the airtightness of the vibrator was confirmed by a He leak test, there was no leak.

<Embodiment 2> FIG. 2 shows a case where a hole 9 for inserting a glass fiber is provided in the case 3. In this case, two options (a) or (b) are possible. If the shape of the hole is, for example, the cross section and shape shown in Figure 3, the glass fiber will have a diameter slightly larger than the diameter of the smaller hole.
Preferred shapes are pillars, cylinders, and spheres (beads). Other than that, a crystal resonator was assembled in the same manner as in Example 5. He
When the airtightness of the vibrator was confirmed by U-cutist,
There were no leaks.

<Embodiment 3> FIG. 4 shows a case where a hole 9 for inserting a glass fiber is provided in the upper lid 4. In this case, either (a) or (b) is possible. Other than that, Example 1
A crystal oscillator was assembled in the same manner. When the airtightness of the vibrator was confirmed using a He1J-cutist, there was no leakage.

<Conventional Example> A crystal resonator was assembled using the conventional sealing method. That is, first, silver was vapor-deposited as an excitation electrode on the crystal plate 2, and it was fixed to 1 using 5. Put these in 3, 3
6 was applied to the edge of the plate, and 1 was temporarily adhered at 4.20°C. These and the periphery of 4, @, which was coated with 6 and temporarily bonded at 4.20°C, were placed opposite each other, and then these were placed in a vacuum heating furnace.
The vacuum was evacuated to LO-6 Tor, r. Afterwards 4
, 30:C, and one mouth sealing was completed.

At this time, many bubbles were observed in the sealed area. When the airtightness and properties of the vibrator were confirmed by a He leak test, it was found that leakage occurred and the airtightness was insufficient.

Effects of the Invention As described above, the sealing method of the present invention has excellent airtightness, and the frequency of a crystal resonator using this method can be finely adjusted and adjusted after sealing. Furthermore, this sealing method has a wide range of application to all products that require vacuum sealing, especially electronic components.

The process drawings and FIGS. 5 and 6 are diagrams showing the structure of a crystal resonator using the conventional sealing method.

1.Lead wire, 2.Crystal plate, 3.Case,
4. Upper lid, 5. Conductive, outer adhesive, 6. Sealing part,
7. Excitation electrode, 8. Glass fiber 9. Hole.

Name of agent: Patent attorney Shigetaka Awano Haka18th Figure 1 Figure 4 \ 3u: is 4 (a) No. figure No. figure

Claims (2)

[Claims] (1) After sealing the case and the top cover with sealing glass except for the hole provided in the sealing part, inserting a glass fiber having a working temperature below the sealing glass into the hole, and then placing it in a vacuum. A sealing method characterized in that the hole is closed by evacuating the inside of the glass fiber and heating it to the working temperature of the glass fiber. (2) After sealing the case or top cover with the hole with sealing glass, inserting a glass fiber having a working temperature below the sealing glass into the hole, then evacuating the inside in a vacuum, and then A sealing method characterized by heating the glass fiber to its working temperature to close the hole.