JPS58100446A - Vacuum sealing method - Google Patents

Abstract

PURPOSE:To perform a reliable sealing by a method wherein a cap is formed by a shape memory alloy, the cap is coupled to the substrate which is provided in the container to be sealed in the low temperature zone, and the substrate is tightened and sealed in the high temperature zone. CONSTITUTION:The cap 10 of shape memory alloy is formed in the shape wherein the pipe 2 will be tightened in base phase, a martensitic transformation is generated at a low temperature, and the diameter of the cap is widened so that it comes into the pipe with a sufficient margin. The cap 10 is covered on the pipe 2 at a low temperature and placed in a vacuum container 5, and the temperature is raised when the container is completely vacuumed. The cap 10 returns to the original shape phase, the pipe 2 is tightened, and a vacuum sealing is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for vacuum sealing metal products.

Conventionally, vacuum sealing of metal products has been carried out by drawing a vacuum from a thin pipe 2 provided in a container 1 and then sealing the pipe 2 as shown in Figure 1.
As shown in Fig. 2, make a hole 4t in a part of the container 1 to be evacuated, place the whole container 1 into a vacuum container 5, and make sure that the inside of the container 1 is sealed. There is a method of sealing the hole 4 with a substance 6 that melts when the temperature is raised, such as solder or glass after the vacuum is created.

In the method shown in FIG. 1, since the pipes 2 are crimped 3, sealing is ensured, but each pipe 2 must be connected to a vacuum device, which has the disadvantage of poor work efficiency. The method shown in Figure 2 allows multiple processes to be performed at the same time, but the disadvantage is that the melting and bonding conditions of solder and glass are affected by the degree of vacuum and the surface condition of the container 1, resulting in variations in the quality of the vacuum packaging. There is.

This invention eliminates the above-mentioned drawbacks and has good workability (
This provides a method for reliably vacuuming and stopping. This invention will be explained below.

The vacuum sealing method according to the present invention is characterized by the use of a shape memory alloy. For example, Ti-Ni alloy, C
Some u-Zn-A1 alloys undergo martensitic phase transformation when cooled.

Even if an alloy that has been transformed into martensite is deformed beyond its elastic limit, it will return to its parent phase state when the temperature is raised, and at that time its shape will also return to its parent phase shape.

With such a shape memory alloy, for example, as shown in FIG. 2. Widen the diameter to 5. Now, cover pipe 2 with cap 1 (l) at low temperature.
When the cap 10 is placed in a vacuum container 5 and the temperature is raised to reach a complete vacuum, the cap 10 returns to the shape of the matrix and tightens the pipe 2, thereby sealing the vacuum. With this method, a large number of processes can be performed at the same time, and vacuum sealing can be ensured.

A method for manufacturing a pressure sensor will now be described as an example. For example, as shown in FIG. 4, a conventional semiconductor pressure sensor includes a diaphragm 11 made of silicon or germanium, a pressure nipple 12, and a vacuum chamber 13. The deformation of the diaphragm 11 is detected by a semiconductor strain gauge embedded in the diaphragm 11, which communicates with the lead i114' and outputs the pressure '1'.
It was kept to a minimum. Conventionally, the vacuum chamber 13 has been constructed by attaching a cap 1u'l:1iL9 to the stem 15, caulking it, placing it in a vacuum, evacuating through the hole 40, and sealing with the substance 6. However, in the method according to the present invention, the cap 1
0 has no hole, and as shown in FIG. 5, several protruding rings @1 @'& are provided on the inner surface, and the shape is such that a complete seal can be achieved when the stem 15Y is tightened. The cap 10 is molded to a size that completely tightens the stem 15 in a high temperature state, and the opening of the cap 10 is widened in a state where martensitic transformation occurs at a low temperature so that the stem 15 can be easily inserted into the cap 10.

Next, the stem 15 and the cap 111' are put together in a low temperature state, placed in the vacuum container 5, the air is removed, and then the temperature is raised.The cap 10 returns to the shape formed by the initial matrix, and the cap 10 becomes the sister of the stem 15. and seal the vacuum.

Of course, such a manufacturing method can be applied not only to pressure cassettes/cassettes, but also to metal vacuum tubes and display devices that utilize electrons in vacuum.

As explained above, in this invention, the cap is formed of a shape memory alloy, and can be bonded to the base provided on the container to be sealed with sufficient margin in the low temperature range, and the cap is tightly sealed in the high temperature range. Therefore, there is an advantage that reliable sealing can be performed without variations in quality compared to conventional solder sealing.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view illustrating an example of a conventional vacuum sealing method, and Fig. 2 is a cross-sectional diagram illustrating an example of another conventional vacuum sealing method.
3 is a schematic sectional view showing one embodiment of the present invention, FIG. 4 is a schematic sectional view of a pressure sensor assembled by a conventional method, and FIG. 5 is a schematic sectional view used when assembling a pressure sensor by the method of the present invention. 1 is a schematic cross-sectional view showing one embodiment of a cap. . In the figure, 1 is a container, 2 is a pipe, 5 is a vacuum container, and 10 is a cap. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Shin Kuzuno (1 other person)

Claims (1)

[Claims] A cap made of a shape-memory alloy is molded to thin and seal the base provided on the container to be vacuum-sealed in a high-temperature range, and is molded to allow sufficient bonding in a low-temperature range. 4. A vacuum sealing method, in which the base is bonded to the base, the interior thereof is evacuated, and then the base is moved to a high temperature range to be vacuum-sealed.