JP2020173982A - Airtight terminal - Google Patents

Abstract

To provide an airtight terminal using composite glass suitable for increasing current capacity.SOLUTION: An airtight terminal 10 includes a metal outer ring 12 having at least one through-hole 11, a lead 13 including at least a low resistance conductor inserted through the through-hole of the metal outer ring, and an insulating glass 14 for sealing the metal outer ring and the lead. The insulating glass is made of composite glass composed of a high-expansion glass inner layer material and an outer layer material of low expansion glass rather than the inner layer material disposed to cover the inner layer material. The inner layer material is made of a glass material selected from a group of, for example, boric acid-based glass, boron silicate-based glass, zinc boric acid-based glass, alkaline boron silicate-based glass, alkaline earth silicate-based glass, and phosphoric acid-based glass.SELECTED DRAWING: Figure 1

Description

The present invention relates to an airtight terminal using a composite glass material as an insulating material.

An airtight terminal is an airtight terminal in which a lead is airtightly sealed in an insertion hole of a metal outer ring via an insulating material, and a current is supplied to an electric device or element housed in the airtight container, or a signal is sent from the electric device or element. Is used when deriving to the outside. In particular, GTMS (Glass-to-Metal-Seal) type airtight terminals that seal the metal outer ring and leads with insulating glass are roughly classified into two types, a matching sealing type and a compression sealing type. In order to ensure highly reliable airtight sealing in the above-mentioned airtight terminals, it is important to properly select the coefficient of thermal expansion of the metal material of the outer ring and the lead and the insulating glass. The insulating glass for sealing is determined by the material of the metal outer ring and lead, the required temperature profile and its coefficient of thermal expansion. In the case of matching sealing, the sealing material is selected so that the coefficients of thermal expansion of the metal material and the insulating glass match as much as possible. On the other hand, for compression sealing, a metal material and an insulating glass material having intentionally different coefficients of thermal expansion are selected so that the metal outer ring compresses the insulating glass and the lead.

In order to ensure high airtight reliability and electrical insulation of conventional airtight terminals, Kovar has the same thermal expansion coefficient as the glass material over a wide temperature range for the metal outer ring and lead material in the matching sealed airtight terminal. Using an alloy (Fe 54%, Ni 28%, Co 18%), both are sealed with insulating glass made of borosilicate glass, and in the compression-sealed airtight terminal, the compressive stress concentric with the glass in the operating temperature range. Uses a metal outer ring made of steel such as carbon steel or stainless steel, and a lead material of an iron alloy such as an iron-nickel alloy (Fe50%, Ni50%) or an iron-chromium alloy (Fe72%, Cr28%). Then, both were sealed with insulating glass made of sodabarium glass.

Japanese Unexamined Patent Publication No. 61-260560

In recent years, there has been a demand for a large current capacity of airtight terminals. For example, there is a growing demand for small, high-performance compressors for refrigerators installed in stores with limited space, such as convenience stores. In this way, compressors in recent years, mainly for commercial use, tend to be smaller than conventional sizes, but the maximum current value that passes through the airtight terminals attached to the compressor increases as the capacity of the refrigerator increases. There is a tendency. Conventionally, for the lead pin of an airtight terminal for a refrigerator, a high resistance metal such as an iron alloy is often used as the lead material from the viewpoint of mechanical strength and heat resistance. For this reason, it can be said that the risk of melting the insulating glass that seals the lead material due to Joule heat at the time of overload has increased, especially in the airtight terminal for high power applications. It has also been proposed to change the lead material of the airtight terminal for high power use from the conventional lead material made of iron alloy to a lead material made of low resistance metal such as copper or aluminum alloy.

In order to increase the current capacity of the airtight terminal, it would be convenient if a lead with a relatively large wire diameter made of a low resistance conductor such as copper or aluminum could be used. However, these low-resistance conductors have a large coefficient of thermal expansion, and when they are sealed with insulating glass of borosilicate glass or soda lime glass, which has a lower coefficient of thermal expansion, they are pulled in the radial direction as the low-resistance conductor leads expand and contract. There is a drawback that stress is generated, and as a result, cracks penetrating the inside of the glass in the direction of the seal interface or the lead axis are generated, and leak defects are likely to occur. Further, in order to match the thermal expansion with the low resistance conductor, when the expansion coefficient of the insulating glass is increased by using a highly alkali metal glass having an increased content of Na ₂ O, K ₂ O, etc., the glass is chemically expanded. There was a problem that it could not be put into practical use because its durability was significantly reduced.

An object of the present invention is to provide an airtight terminal using a composite glass suitable for increasing the current capacity.

According to the present invention, a metal outer ring having at least one through hole, a lead including a low resistance conductor inserted through the through hole of the metal outer ring, and an insulating glass for sealing the metal outer ring and the lead. The insulating glass is provided with an airtight terminal composed of an inner layer material of a highly expanding glass and a composite glass composed of an outer layer material of a lower expansion glass than the inner layer material covering at least the outer diameter portion of the inner layer material. Glass. In the above insulating glass, a high expansion glass having inferior chemical durability is used as a sealing material for an airtight terminal by providing an outer layer material made of a glass having a lower expansion on the surface of the inner layer material of the high expansion glass. Since the exposed surface of the high expansion glass is covered with the outer layer material of the low expansion glass, it can be used without worrying about the chemical durability of the inner layer glass. Further, in the process of cooling from heating at the time of sealing, the glass of the outer layer material is strengthened by utilizing the large compressive stress generated in the outer layer material due to the shrinkage of the inner layer material, and the mechanical strength of the outer layer material glass is improved.

The plan view of the airtight terminal 10 which concerns on this invention is shown. A front view of the airtight terminal 10 according to the present invention is shown, and a front partial cross-sectional view cut along the DD line of FIG. 1 is shown. The bottom view of the airtight terminal 10 which concerns on this invention is shown. The plan view of the airtight terminal 20 which concerns on this invention is shown. A front view of the airtight terminal 20 according to the present invention is shown, and a front partial cross-sectional view cut along the DD line of FIG. 4 is shown. The bottom view of the airtight terminal 20 which concerns on this invention is shown.

As shown in FIGS. 1 to 3, the airtight terminal 10 according to the present invention has a metal outer ring 12 having at least one through hole 11 and at least a low resistance inserted through the through hole 11 of the metal outer ring 12. A lead 13 including a conductor and an insulating glass 14 for sealing the metal outer ring 12 and the lead 13 are provided, and the insulating glass 14 includes an inner layer material 14a of a highly expanding glass arranged on the side of the lead 12 and an inner layer material. It is made of a composite glass that covers the outside of 14a and is arranged on the side of the metal outer ring 12 and is composed of an outer layer material 14b that is a lower expansion glass than the inner layer material 14a. With the above configuration, while using a low resistance conductor such as copper or aluminum which is advantageous for improving the current capacity or a lead 13 containing these low resistance conductors, the lead 13 is matched to the coefficient of thermal expansion and cooled from heating at the time of sealing. An airtight terminal having a composite glass insulating material in which the glass of the outer layer material 14b is strengthened by utilizing the large compressive stress generated in the outer layer material due to the shrinkage of the inner layer material 14a in the process and the mechanical strength of the outer layer material glass is improved. provide.

The metal outer ring 12 is made of iron or an iron-based alloy, and the lead 13 is a low resistance conductor such as copper, copper alloy, aluminum or aluminum alloy, or as shown in FIG. 5, a steel core material 23a is formed of copper, copper alloy, aluminum, etc. It is composed of a composite metal lead 23 provided with an outer cover material 23b of a low resistance conductor such as an aluminum alloy. The steel material is not particularly limited, but for example, JIS-SUH309, SUH310, SUH409, SUH409L, SUH446 and the like are preferable.

As the inner layer material 14a constituting the insulating glass 14, any material may be used as long as it is a glass material having a higher expansion than the outer layer material 14b. For example, the linear expansion rate of the inner layer material 14a is in the range of 12 to 18 ppm / K, borate-based glass (B ₂ O ₃ ), boron silicate-based glass (B ₂ O _3- SiO ₂ ), and zinc borate-based glass (B). ₂ O _3- ZnO), alkaline boron silicate-based glass (SiO _2- B ₂ O _3- R ₂ O [R is alkali metal]), alkaline earth silicate-based glass (SiO _2- RO [R is alkaline earth metal] ]), A glass material selected from the group of phosphoric acid-based glass (P ₂ O ₅ ) can be used, and more preferably boric acid-based glass (B ₂ O ₃₎ having a linear expansion rate in the range of 12 to 16 ppm / K. ), boron silicate glass _{(B 2 O 3 -SiO 2)} , zinc borate based glass _{(B 2} O 3 -ZnO), alkali borosilicate glass _{(SiO 2 -B 2 O 3 -R} 2 O [R is It is preferable to use a glass material selected from the group of alkali metal]), alkaline earth silicate-based glass (SiO _2- RO [R is alkaline earth metal]), and phosphoric acid-based glass (P ₂ O ₅ ). The inner layer material 14a preferably does not invade the leads 13 and is difficult to diffuse into the outer layer material 14b and does not disappear. As the outer layer material 14b of the insulating glass 14, any material may be used as long as it is a glass material having lower expansion than the inner layer material 14a and having excellent chemical durability and weather resistance. For example, soda lime glass having a linear expansion coefficient of 8 to 8.5 ppm / K is suitable. The outer layer material 14b becomes tempered glass by utilizing a large compressive stress due to shrinkage of the inner layer material 14a in the cooling process at the time of sealing the insulating glass 14.

Although the three-terminal airtight terminal is illustrated in the present specification, any form may be used as long as the lead is glass-sealed in the outer ring, and the airtight terminal is not limited to the illustrated airtight terminal.

As shown in FIGS. 1 to 3, the airtight terminal 10 of the first embodiment according to the present invention has a metal outer ring 12 of carbon steel having three through holes 11 and a through hole 11 of the metal outer ring 12. A copper alloy lead 13 inserted into the lead 13 and an insulating glass 14 for sealing the metal outer ring 12 and the lead 13 are provided, and the insulating glass 14 is arranged on the side of the lead 12 and has a linear expansion rate of 12 ppm / K. The linear expansion rate of the inner layer material 14a of the alkaline boron silicate-based glass (SiO _2- B ₂ O _3- R ₂ O) and the linear expansion rate of 8 ppm / K arranged on the side of the metal outer ring 11 covering the outside of the inner layer material 14a. It is made of a composite glass composed of an outer layer material 14b of soda lime glass.

As shown in FIGS. 1 to 3, the airtight terminal 10 of the second embodiment according to the present invention has a metal outer ring 12 of stainless steel having three through holes 11 and a through hole 11 of the metal outer ring 12. A copper alloy lead 12 inserted into the lead 12 and an insulating glass 13 for sealing the metal outer ring 11 and the lead 12 are provided, and the insulating glass 13 is arranged on the side of the lead 12 and has a linear expansion rate of 16 ppm / K. The inner layer material 13a of phosphoric acid-based glass (P ₂ O ₅ ) and the outer layer material of soda lime glass having a linear expansion ratio of 8.3 ppm / K arranged on the side of the metal outer ring 11 so as to cover the outside of the inner layer material 13a. It is made of a composite glass composed of 13b.

As shown in FIGS. 4 to 6, the airtight terminal 20 of the third embodiment according to the present invention has a metal outer ring 22 of stainless steel having three through holes 21 and a through hole 21 of the metal outer ring 22. A composite metal lead 23 in which a copper alloy outer cover material 23b is applied to a core material 23a of a steel material inserted into the lead, and an insulating glass 24 for sealing the metal outer ring 22 and the lead 23 are provided. An inner layer material 24a of an alkali boron silicate-based glass (SiO _2- B ₂ O _3- R ₂ O) having a linear expansion rate of 15 ppm / K arranged on the side of 23 and a metal outer ring covering the outside of the inner layer material 24a. It is composed of a composite glass arranged on the side of 22 and composed of an outer layer material 24b of soda lime glass having a linear expansion rate of 8.3 ppm / K.

As shown in FIGS. 4 to 6, the airtight terminal 20 of the fourth embodiment according to the present invention has a metal outer ring 22 of stainless steel having three through holes 21 and a through hole 21 of the metal outer ring 22. A composite metal lead 23 in which a copper alloy outer cover material 23b is applied to a core material 23a of a steel material inserted into the lead, and an insulating glass 24 for sealing the metal outer ring 22 and the lead 23, and the insulating glass 24 is a lead. and the inner layer member 24a of 23 side to arranged the linear expansion coefficient 12 ppm / K of zinc borate glass _{(B 2} O 3 -ZnO), covering the outside of the inner layer member 24a arranged on the side of the metal outer ring 22 It is composed of a composite glass composed of an outer layer material 24b of soda lime glass having a linear expansion ratio of 8 ppm / K.

As the outer cover material of the airtight terminal according to the present invention, a material having a desired finish plating such as nickel, nickel phosphorus, nickel boron, etc. can also be used. Further, the core material described in the above embodiment may be any material as long as it can form the base structure of the outer cover material. For example, the core material is not limited to steel material and stainless steel, and Fe—Ni alloy and Fe—Cr are appropriately used. It may be changed to an alloy or the like. Similarly, as the outer layer material described in the examples, any glass material can be used as long as it is a glass material having lower expansion than the inner layer material and having excellent chemical durability and weather resistance, not limited to soda-lime glass. For example, borosilicate glass, soda-lime glass, alkaline earth aluminosilicate glass, boron silicate glass, alkaline boron silicate glass and the like can be used. An insulating coating such as silicone resin may be attached to a part of the lead of the airtight terminal and the outer ring of the metal of the present invention.

INDUSTRIAL APPLICABILITY The present invention can be applied to an airtight terminal that is particularly durable against high voltage and high current and requires high airtightness.

Airtight terminal 10, through hole 11, metal outer ring 12, lead 13, insulating glass 14, inner layer material 14a, outer layer material 14b, airtight terminal 20, through hole 21, metal outer ring 22, lead 23, core material 23a, outer cover Material 23b, insulating glass 24, inner layer material 24a, outer layer material 24b.

Claims (10)

An insulating glass for sealing a metal outer ring having at least one through hole, a lead including at least a low resistance conductor inserted through the through hole of the metal outer ring, and the metal outer ring and the lead 12. The insulating glass is an airtight terminal made of a composite glass composed of an inner layer material of high-expansion glass and an outer layer material of lower expansion glass than the inner layer material arranged so as to cover the inner layer material. The inner layer material is a glass material selected from the group of boric acid-based glass, boron silicate-based glass, zinc boric acid-based glass, alkaline boron silicate-based glass, alkaline earth silicate-based glass, and phosphoric acid-based glass. The airtight terminal according to 1. The airtight terminal according to claim 1 or 2, wherein the inner layer material has a linear expansion coefficient in the range of 12 to 18 ppm / K. The airtight terminal according to any one of claims 1 to 3, wherein the lead is a composite metal lead in which a core material is coated with a low resistance conductor outer cover material. The airtight terminal according to claim 4, wherein the surface of the outer cover material is plated. The airtight terminal according to claim 5, wherein the plating is made of nickel, nickel phosphorus, or nickel boron. The airtight terminal according to any one of claims 4 to 6, wherein the core material is a metal material selected from the group of steel, stainless steel, Fe—Ni alloy, and Fe—Cr alloy. The airtight terminal according to any one of claims 1 to 7, wherein the low resistance conductor is made of a metal material selected from the group of copper, copper alloy, aluminum, and aluminum alloy. The airtight terminal according to any one of claims 1 to 8, wherein the outer layer material is made of a glass material having lower expansion than the inner layer material and having excellent chemical durability and weather resistance. The airtight terminal according to claim 9, wherein the outer layer material is a glass material selected from the group of soda-lime glass, borosilicate glass, soda barium glass, alkaline earth aluminosilicate glass, boron silicate glass, and alkaline boron silicate glass.

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