JPH0380351B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an airtight terminal used in an airtight package for airtightly enclosing circuit elements and the like, and a method for manufacturing the same. As shown in FIG. 1, this type of airtight package has a lead wire insertion hole 3 formed in a base 1 through which the lead wire 2 is inserted.
is inserted into the lead wire insertion hole 3 and sealed with an insulating material 4 such as glass, and a circuit element 5 etc. is connected to the inner end of the lead wire 2 of the airtight terminal T, which is covered with a cap 6. The circuit element 5 and the like are hermetically sealed. FIG. 2 is a sectional view of such an airtight terminal T, and the same reference numerals as in FIG. 1 indicate the same parts. Conventionally, when sealing the lead wire 2 into the lead wire insertion hole 3 formed in the base 1, there have been roughly two types of methods. In other words, Kovar is used as the base material and lead wire, and glass is used as the insulating material.
The so-called matting method is used to seal the Kovar material using glass for sealing it, which has the same expansion coefficient as the Kovar material, and uses iron material as the base material and lead wire, while sealing it using glass for sealing the iron as the glass. This is the so-called compression method.
According to the compression method, since glass and iron have different expansion coefficients, the iron material is compressed by the expansion of glass. Since the airtight terminal manufactured by the above-mentioned matching method uses hard Kovar material for the base and lead wire, it has the advantage of being strong and durable, but has the disadvantage of being expensive. On the other hand, airtight terminals manufactured using the compression method have a base material,
Since iron is used as the lead wire, it has the advantage of being inexpensive, but since iron is soft, it has the disadvantage that the lead wire is particularly prone to breakage and lacks durability. The present invention has been made in view of the above-mentioned points, and aims to manufacture a good hermetic terminal by taking advantage of the advantages of the compression method and the matching method.
That is, it is an object of the present invention to provide a durable and inexpensive airtight terminal and a method for manufacturing the same. To summarize the present invention, the airtight terminal according to the present invention is an airtight terminal in which a lead wire is inserted into the lead wire insertion hole of a base having a lead wire insertion hole and sealed with glass, wherein the base is made of iron material, The lead wire is made of Kovar material, and the sealing glass is a two-component mixed glass comprising 10 to 70% by weight of Kovar alloy sealing glass and 30 to 90% by weight of iron sealing glass. be. Further, according to the method for manufacturing an airtight terminal according to the present invention, a lead wire is inserted into the lead wire insertion hole of a base having a lead wire insertion hole, and a sealing glass is filled, the glass is melted, and then solidified. In the method for manufacturing a terminal, the base is made of iron, the lead wire is made of Kovar,
The sealing glass is characterized in that it is manufactured from a two-component glass containing 10 to 70% by weight of Kovar sealing glass and 30 to 90% by weight of iron sealing glass. According to the airtight terminal according to the present invention, since inexpensive iron is used as the base and Kovar is used as the lead wire, the cost of the airtight terminal can be reduced and it can be made to have excellent durability. Further, according to the method for manufacturing an airtight terminal according to the present invention, sealing is performed using a sealing glass made of a mixture of Kovar material sealing glass and iron sealing glass as the sealing glass. There is an advantage in that it is possible to manufacture an airtight terminal in which the lead wire is made of Kovar and the base is made of iron, without causing glass cracks, that is, maintaining sufficient airtightness. The present invention will be explained in more detail. FIG. 2 is a cross-sectional view showing one embodiment of the airtight terminal of the present invention. As is clear from FIG. A lead wire 2 is inserted through the lead wire insertion hole 3, and the lead wire 2 is sintered and sealed with glass 4. In the hermetic terminal T according to the invention, the base material is iron, while the lead wire 2 is made of Kovar material. Further, as the sealing glass, a two-component mixed glass consisting of 10 to 70% Kovar sealing glass and 30 to 90% iron sealing glass is used. This kind of special sealing glass is used because it is a compression type iron sealing glass, and the lead wire 2 made of Kovar material as mentioned above is used.
When it is sintered and sealed on the iron base 1, radial cracks occur in the glass near the lead wire insertion part 7, and on the other hand,
This is because when sintering and sealing is performed using Kovar sealing glass, linear glass cracks occur near the base 1. Such cracks significantly impair airtightness, and the allowable leakage value is 1.0×10 ^-7 atm・
In addition to exceeding cc/sec, the insulation properties also deteriorate, making it unusable. The Kovar sealing glass used in the present invention may be any glass that has conventionally sealed the Kovar material of this type of hermetic terminal T. For example, it can be borosilicate glass. On the other hand, the glass for iron sealing is not limited in the present invention, and any glass that has been conventionally used for sealing iron materials in airtight terminals may be used. For example, soda barium glass can be used. As mentioned above, the mixing amount of the Kovar sealing glass and the iron sealing glass is 10 to 70% for the Kovar sealing glass and 30 to 90% for the iron sealing glass, but the Kovar sealing glass exceeds 70%. If the iron sealing glass exceeds 90%, radial glass cracks will occur near the base 1 at the lead wire insertion portion. Although the base 1 is made of iron, it may be plated with nickel or the like in consideration of airtightness. Furthermore, the Kovar material of the lead wire 2 may be one with an oxide film formed on its surface. By forming such an oxide film,
Improves airtightness and thermal shock resistance. Next, a method for manufacturing an airtight terminal according to the present invention will be explained. First, glass powders of 10 to 70% Kovar sealing glass and 30 to 90% iron sealing glass are mixed, heated above the glass softening point, and melted and mixed. In the present invention, the softening point is about 1000°C. Next, the glass pieces are cooled and crushed into granules of approximately 80 meshes or more, which are then press-molded into a desired shape. The sealing glass produced by optionally pre-sintering at 600 to 750°C and removing the binder is filled into the lead wire insertion hole 3 of the base 1 made of iron, together with the lead wire 2 made of Kovar material, and heated at a desired temperature. Sintered,
Seal. Examples of the present invention will be described below. Example A lead wire 2 was sealed to a base 1 using a sealing glass manufactured from borosilicate glass % soda barium glass %. As the lead wire 2, Kovar material was etched and cleaned, then annealed at 700 to 950°C, and then oxidized to form an oxide film (hereinafter referred to as A), and after etching, annealed at 700 to 950°C. An airtight terminal was manufactured using both of the terminals that were only subjected to treatment and no oxide film was formed (hereinafter referred to as B). The lead wire 2 of the manufactured airtight terminal T was pulled along the axis at a pulling speed of 170 mm/min until the lead wire 2 could be pulled out, and the limit value thereof was measured. For reference, the mechanical properties of airtight terminals (indicated as C and D, respectively) manufactured by the conventional compression method (iron base - iron lead wire) and matching method (Kovar base - Kovar lead wire) were measured. . The results are summarized in Table 1.

[Table] The pull-out limit values of the airtight terminals A and B according to the present invention are of course higher than those of the conventional airtight terminal C (compression type), as well as those of the airtight terminal D (matching type).
It was an improvement over the previous one. This differs from conventional mating systems in that the base material, lead wires,
This is thought to be because the lead wire 2 is under some pressure because the expansion coefficients of the glasses are different. In addition, when manufacturing the airtight terminal according to the present invention,
To remove residual strain, strain relief treatment may be performed after sintering. As explained above, according to the present invention, since iron is used as the base material and Kovar material is used as the lead wire, an advantage is that an airtight terminal with excellent durability can be manufactured at a lower cost than in the past. be.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of the airtight package, and FIG. 2 is a sectional view of the airtight terminal T. 1...Base, 2...Lead wire, 3...Lead wire insertion hole, 4...Glass.

Claims (1)

[Scope of Claims] 1. An airtight terminal in which a lead wire is inserted into the lead wire insertion hole of a base having a lead wire insertion hole and sealed with glass, wherein the base is made of iron, the lead wire is made of Kovar, and further An airtight terminal characterized in that the sealing glass is manufactured from a two-component glass consisting of 10 to 70% Kovar alloy sealing glass (weight %, same hereinafter) and 30 to 90% iron sealing glass. 2 Insert a lead wire made of Kovar material into the lead wire insertion hole of the base made of iron material having a lead wire insertion hole, and fill it with sealing glass made from the following two-component glass and heat it. A method for producing an airtight terminal, characterized in that the sealing glass is melted and then solidified; Kovar alloy sealing glass 10-70% iron sealing glass 30-90%.