JPH0436064Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to an improvement in airtight terminals for, for example, crystal oscillators.

Conventional technology Conventionally, for example, a secret terminal for a crystal oscillator is
As shown in the figure, lead wires 2, 2 are passed through a metal outer ring 1 having a substantially cap shape with the open end curled outward and sealed with glass 3. After sealing the glass 3, We perform copper plating, tin plating, etc.

Further, in this type of airtight terminal, the metal outer ring 1 and the lead wires 2 are usually made of a metal material (for example, Kovar) having a linear expansion coefficient approximately equal to that of the sealing glass 3. It is a so-called mating seal type.

Problems to be solved by the invention Although it is a matching seal type, the linear expansion coefficient of the metal outer ring 1 is slightly larger than that of the glass 3, so after the sealing of the glass 3 is completed, the metal outer ring 1 The amount of shrinkage when the glass returns to room temperature is slightly larger than the amount of shrinkage of the glass 3, and as a result, the glass 3 forms a seal (hereinafter referred to as a compressor) under a compressive force from the metal outer ring 1. (referred to as the "Shion Seal").

Therefore, due to the current and temperature of the plating performed after sealing the glass 3, the compression force of the metal outer ring 1 is released (compression is removed), and the metal outer ring 1
A classic C occurs in the glass 3 at a position close to the curled portion 1a and the sealed end of the glass 3. This classic C has a metal outer ring 1 as shown in FIG.
It occurs in a shell-like shape along the inner diameter surface. Therefore,
By increasing the thickness of the oxide film on the metal outer ring 1 and by creating an oxidizing atmosphere in the furnace when sealing the glass 3, the sealing strength is increased and the occurrence of shell-like classic C is prevented. It's on, but it's unstable.
There was a problem with the lack of certainty.

This problem is caused by the curled portion 1a of the metal outer ring 1.
Although this is not a flat shape, it is more likely to occur in those having a curled portion 1a, and this is presumed to be due to the bending stress when curled, in addition to the difference in the amount of shrinkage.

Means for Solving the Problems The present invention was proposed in view of the above problems, and includes a metal outer ring having an outwardly curled portion on the open end side, and a lead passing through the metal outer ring. An airtight terminal in which wires are sealed with glass, characterized in that a beveled part is formed around the entire circumference of the curled part of the metal outer ring in a position close to the sealed end of the glass. It is.

Effect: Due to the surface punching process, the curled portion of the metal outer ring in the vicinity of the seal end of the glass is work-hardened and its strength is improved. As a result, it is possible to prevent shell-like cracks from occurring during plating performed after glass sealing.

Embodiment FIG. 1 shows a vertical sectional side view when the present invention is applied to an airtight terminal for a crystal oscillator, and FIG. 2 shows an enlarged sectional view of the main part. , 11 is a metal outer ring, 12 is a lead wire, and 13 is glass.

The metal outer ring 11 has a substantially cap shape with a curled portion 11a whose open end side is curled outward, and lead insertion holes 11b, 1 are formed in the outer wall portion of the closed end side.
1b, and is made of a metal material having substantially the same coefficient of linear expansion as the glass 13, as in the conventional case.

Then, a beveled portion A is formed around the entire circumference of the curled portion 11a of the metal outer ring 11 at a position close to the sealed end of the glass 13.

The above-mentioned surface stamping section A may be processed by any method, but it is most desirable to use a press.

The metal outer ring 11 with the faceted portion A formed thereon as described above has its open end facing upward, and the lead wire 1
2 and 12 and a tablet-shaped glass 13, positioned and held in a glass sealing jig (not shown),
The glass is sealed in a glass sealing furnace as shown in FIG. That is,
The tablet-shaped glass 13 is heated and melted in a glass sealing furnace, and is applied around the lead wires 12, 12, the inside of the metal outer ring 11, and the lead insertion hole 11b,
Fill in the gap around 11b. After that, it is cooled in a slow cooling furnace.

The lead wires 12, 12 are made of a metal material having a linear expansion coefficient substantially equal to that of the glass 13.

After the glass sealing, the lead wires 12, 12 are plated with copper, tin, etc.

The heat during the above plating is applied to the glass 13 and the metal outer ring 1.
1, the present invention forms a beveled part A around the entire circumference of the curled part 11a of the metal outer ring 11 at a position close to the seal end of the glass 13. Since the portion A is work-hardened and has improved strength, it is possible to prevent shell-like cracks from occurring around the seal end of the glass 13 due to compression failure.

Although the above explanation has been made regarding hermetic terminals for crystal oscillators, the present invention can be applied to all hermetic terminals that have a matching seal type metal outer ring with an outwardly curled portion on the open end side. be.

Effects of the invention According to the invention, with a relatively simple configuration,
During copper plating and tin plating performed after glass sealing, it is possible to reliably prevent shell-like cracks from occurring around the sealed end of the glass, thereby improving yield in the manufacturing process of airtight terminals.

[Brief explanation of drawings]

Fig. 1 is a vertical side view of a hermetic terminal for a crystal oscillator in which the present invention is applied, Fig. 2 is an enlarged sectional view of the main part of Fig. 1, and Fig. 3 is a conventional airtight terminal for the same purpose. FIG. 4 is an end view seen from below. 11... Metal outer ring, 11a... Curl part, 13
...Glass, A...Surfacing processing section.

Claims (1)

[Scope of utility model registration request] In an airtight terminal in which a metal outer ring having an outwardly curled portion on the open end side and a lead wire passing through the metal outer ring are sealed with glass, the curled portion of the metal outer ring is connected to the sealed end of the glass. 1. An airtight terminal characterized in that a faceted part is formed around the entire circumference at a position close to the part.