JPS6035966Y2 - airtight terminal - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an airtight terminal, and particularly to an airtight terminal used as a holder for a crystal resonator, for example.

An airtight terminal used as a cold welding type crystal oscillator holder has a structure shown in FIGS. 1 and 2.

In the figure, 1 is a boat-shaped metal outer ring made of a soft metal that can be cold-welded, such as copper 2, and a metal that can be sealed with glass, such as Kovar (54% Fe, 23% Ni, 18% CO).
It is manufactured by press-molding a lattice material, and has a top plate part 4, a cylindrical part 5, and a flange part 6. The inner surface is Kovar 3.

The top plate portion 4 has two through holes 7 near both ends in the longitudinal direction.
, 7 are provided, and a protrusion 8 for regulating the glass position is provided on the inner surface of the cylindrical portion 5.

Kovar lead wires 9, 9 are loosely inserted into the through holes 7, 7, and the metal outer ring 1 and the lead wires 9.9 are hermetically and insulatively sealed via a borosilicate glass 10. There is.

The glass 10 is filled and sealed to the middle of the depth of the metal outer ring 1, that is, to the position of the protrusion 8, and a void 11 is formed below.
is formed.

A direct bending vibration type crystal resonator is fixed to the inner ends of the lead wires 9, 9 (upper part of FIG. 2), or a spring support is fixed and the crystal resonator is supported on this spring support. A metal cap is placed over the metal cap, and the flange portion thereof is overlapped with the flange portion 6 of the metal outer ring 1 and sealed by cold pressure welding.

This cold pressure welding is used for sealing. As the cylindrical portion 5 and flange portion 6 of the metal outer ring 1 are deformed toward the center due to the pressure welding stress during cold welding, the cavity 11 below the glass 10 becomes a space to accommodate these deformations. Then,
In addition, the protrusion 8 restricts the deformation of the cylindrical portion 5 due to the stress to occur at a position below the sealed portion of the glass 10, thereby preventing the glass 10 from cracking.

By the way, the metal outer ring 1 is made of Fe* as described above.
It is formed using Kovar, which is a Ni*Co alloy, but this type of Kovar is extremely expensive due to the rising price of cobalt, and it is also extremely expensive because it is press-molded from a clad material of cobalt and copper. .

In order to reduce the cost of the metal outer ring 1, the metal outer ring 1 may be made smaller.

However, the length and width W of the metal outer ring 1
etc. are approximately determined by the dimensions of the crystal resonator to be enclosed, and it is difficult to miniaturize the crystal resonator.

On the other hand, when the height dimension H is reduced, the wall thickness T of the glass 10 becomes smaller, and the lead wires 9, 9 and the glass 1
There is a problem that the airtightness and sealing strength of the sealed portion with 0 are reduced.

Therefore, the main purpose of this invention is to provide an airtight terminal in which the metal outer ring is downsized without reducing the airtightness and sealing strength, and the cost of the metal outer ring can be reduced.

To summarize, this invention is characterized by making the glass thickness only around the lead wires larger than in other parts.

An embodiment of this invention will be described below with reference to the drawings.

FIG. 3 shows a sectional view thereof, and FIG. 4 shows a bottom view thereof.

In the figures, the same or corresponding parts as in FIGS. 1 and 2 are given the same reference numerals.

The first difference from FIGS. 1 and 2 is that the height of the metal outer ring 1 is set smaller than the conventional H.

Therefore, the wall thickness t of the glass 10 is also smaller than the conventional thickness T.

Second, in the glass 10 where the wall thickness t is reduced overall as described above, local thickened portions 10a, 10a are provided particularly only in the portion along the lead wire 9°9.

According to the above configuration, by reducing the height dimension of the metal outer ring 1 to h, the material cost can be reduced in proportion to H-h, and moreover, the sealing between the lead wires 9, 9 and the glass 10 can be achieved. The airtightness and sealing strength of the attached part are determined by the thick part 10a of the glass 10.
, 10a, for example, if h=T,
It can be made no inferior to the conventional one, and the intended purpose of reducing the cost of airtight terminals can be achieved without reducing the airtightness and sealing strength.

Note that the sealed portion between the metal outer ring 1 and the glass 10 extends over the top plate portion 4 and the cylindrical portion 5, so even if the height dimension of the metal outer ring 1 and the wall thickness of the glass 10 are reduced, the sealing portion still remains. Since the dimensions of the sealing interface are sufficiently large, deterioration in airtightness and sealing strength does not substantially pose any problem.

In addition, this invention has a particularly remarkable effect in cold welding type airtight terminals that use a metal outer ring press-molded from a copper and Kovar clad material, but it is also In the airtight terminal of the mold, it is possible to reduce the cost by reducing the amount of expensive Kovar used.

As described above, this idea forms a thicker part in the part along the glass lead wire than in other parts, so the height of the metal outer ring can be reduced without reducing airtightness or sealing strength. ,
This has the effect of reducing costs.

[Brief explanation of the drawing]

Figure 1 is a plan view of a cold pressure welding type airtight terminal which is the background of this invention, Figure 2 is a sectional view taken along the line ■-■ in Figure 1, and Figure 3
The figure is a sectional view of a cold pressure welding type airtight terminal according to an embodiment of the invention, and FIG. 4 is a bottom view of FIG. 3. 1...Metal outer ring, 2...Copper, 3...
... Kovar, 4... Top plate section, 5...
・Cylindrical part, 6... Flange part, 7...
Through hole, 8...protrusion, 9...lead wire,
10...Glass, 10a...Thick wall part,
11... Void.

Claims (1)

[Scope of utility model registration request] The lead wires are inserted into the through holes provided at both ends of the top plate of the boat-shaped metal outer ring, and glass is filled halfway into the metal outer ring to create an airtight insulation between the metal outer ring and the lead wires through the glass. What is claimed is: 1. An airtight terminal, characterized in that a thicker portion is formed in a portion along the lead wire of the glass than in other portions.