JP3012255B2 - Manufacturing method of hermetic terminals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a method for manufacturing an airtight terminal having a water-repellent film provided on a glass surface.

[Prior art]

Hermetic terminals are widely used in electric equipment in various fields, and there are various shapes and structures depending on applications. Basically, as shown in FIG. The lead 3 is hermetically sealed via the glass 2, and the insulating property between the metal outer ring 1 and the lead 3 is ensured by the glass 2. There are two types of hermetic terminals: one called a compression sealing type and one called a matching sealing type. In the former, the airtight outer ring 1 is made of iron or low carbon steel, soda glass such as soda barium glass or soda lime glass is used as the glass 2, and an iron-nickel alloy (Fe50%, Ni50%) is used as the lead 3. The linear expansion coefficient α ₁ of the metal outer ring 1 and the linear expansion coefficient α _{2 of the} glass are set in a relationship of α ₁ > α ₂ so that a strong compressive stress is applied to the glass 2 by the metal outer ring 1. It was done. A compression-sealed type using a borosilicate glass as the glass 2 and an iron-nickel-cobalt alloy (Fe53%, Ni28%, Co18%) as the lead 3 is currently in practical use. on the other hand,
In the latter, the metal outer ring 1 and the lead 3 are formed of an iron-nickel-cobalt alloy (Fe53%, Ni28%, Co18%) and borosilicate glass is used as the glass 2. Coefficient of linear expansion α ₁ , α ₃ and glass 2
Of the coefficient of linear expansion alpha ₂ is obtained by setting the relationship _{α 1 = α 3 ≒ α 2} . The former is advantageous in that it is inexpensive and has high mechanical strength, but on the other hand, concentric compressive strain is applied to the glass 2, there are design restrictions on the sealing part, and the insulation of the surface of the glass 2 changes with temperature. There is a disadvantage that it is easy. The latter has advantages such as being stable due to no distortion in a wide temperature range, the shape can be arbitrarily designed, the reliability of airtightness is high, and the stability of the insulating property of the surface of the glass 2 is good.
It is expensive and has relatively poor mechanical strength. As described above, the compression-sealing type and the matching sealing type have different advantages and disadvantages, so that they are selectively used depending on the application. When soda barium glass or borosilicate glass is left in high temperature and high humidity, the insulation resistance and the withstand voltage decrease. In particular, in soda barium glass, since the component soda easily bonds to moisture, these tendencies are large. Therefore, there is a problem that the insulation performance between the metal outer ring 1 and the lead 3 may be deteriorated. This is clearly shown in the graph of FIG. 5 showing the relationship between the surface resistance and the humidity of the glass. Therefore, a water-repellent film 4 is conventionally provided by applying a silicone oil such as dimethylsiloxane on the surface of the glass 2, or dimethyldichlorosilane or diethyldichlorosilane as disclosed in Japanese Patent Publication No. 64-796. The water-repellent film 4 is provided by applying chlorosilane such as chlorosilane.

[Problems to be solved by the invention]

However, the water-repellent film 4 made of silicon oil as described above has almost no effect of preventing the insulation resistance from lowering. Therefore, the water-repellent film 4 made of chlorosilane is formed on the surface of the glass 2 in Japanese Patent Publication No. 64-796. Is provided to block the influence of moisture and prevent the insulation resistance from lowering. However, chlorosilane has a risk of generating chlorine gas and has a problem of affecting the human body. Further, the water-repellent film 4 made of chlorosilane is formed on the surface of the metal outer ring 1 other than the surface of
If the airtight terminal is attached to an electrical device such as a relay, poor welding or poor soldering may occur when the airtight terminal is attached to the surface of the metal ring. A special device for removing the film 4 is required. The present invention has been made in view of the above points, and there is no danger that toxic gas is generated from the water-repellent film, and there is no need to remove the water-repellent film from the outer metal ring or the lead. It is an object of the present invention to provide a method for manufacturing a terminal.

[Means for Solving the Problems]

In the method for manufacturing a hermetic terminal according to the present invention, the metal outer ring 1 and the lead 3 are hermetically and insulated and sealed via the glass 2,
After the finish plating is formed by gold plating on the outer metal ring 1 and the lead 3, alkoxysilane or silazane is applied to the surface of the glass 2, the outer metal ring 1 and the lead 3 to form the water-repellent film 4. Is what you do.

[Operation]

In the present invention, after the metal outer ring 1 and the lead 3 are finished plated by gold plating, the glass 2 and the metal outer ring 1 are formed.
The water-repellent film 4 is formed by applying alkoxysilane or silazane to the surface of the lead 3 and the lead 3, and the alkoxysilane or silazane does not generate toxic gas. Also, without removing the water-repellent film 4 made of alkoxysilane or silazane, it is possible to perform soldering to the finish-plated lead 3 or welding to the metal outer ring 1.

【Example】

Hereinafter, the present invention will be described in detail with reference to examples. FIG. 2 is a block diagram showing a process for manufacturing a matched-sealing type hermetic terminal. Try to increase the adhesion. As the glass 2, soda glass such as soda barium glass or soda lime glass, borosilicate glass, or the like can be used. The glass powder is kneaded with a binder or the like, and the binder is burned off by molding and heating. A glass tablet is made by binding glass powder locally,
And a glass tablet and a lead 3 inside the metal outer ring 1
By disposing and heating the glass tablet, the glass tablet is melted, and as shown in FIG.
Next, after removing the oxide film on the exposed surfaces of the metal outer ring 1 and the leads 3, an Ni plating layer is formed by performing electroplating or chemical plating on the exposed surfaces of the metal outer ring 1 and the leads 3; Next, further electroplating or chemical plating is performed and Au plating is performed to form a finish plating layer. Thereafter, a water-repellent film 4 is formed on the surface of the glass 2. Water repellent film 4
Is dimethylmethoxysilane [(CH ₃ ) ₂ Si (OCH ₃ ) ₂ ]
And the like, alkoxysilane and hexamethyldisilazane [(CH
_{3) 3} SiNHSi (CH ₃₎ and those formed by the silazane _3] such as 1 these alkoxysilanes or silazanes coating, spray, is deposited on the surface of the glass 2 by dipping at about 200 ° C. The water-repellent film 4 is formed on the surface of the glass 2 by heating and drying for about an hour. The water-repellent film 4 may be formed on the entire sealed terminal including the exposed surface of the metal outer ring 1 and the lead 3, and the water-repellent film 4 may be formed on the exposed surface of the metal outer ring 1 and the lead 3. It is not necessary to remove the film 4 in particular. FIG. 3 is a block diagram showing a process of manufacturing a compression-sealing type hermetic terminal. First, a metal outer ring 1 is subjected to electroplating to form a Ni plating layer, and thereafter, a case of a matching sealing type. The glass tablet and the lead 3 are arranged inside the metal outer ring 1 in the same manner as in
And the metal outer ring 1 and the lead 3 are hermetically and insulated and sealed. Then, similarly to the case of the matching sealing type, the exposed surface of the metal outer ring 1 and the exposed surface of the lead 3 are subjected to electroplating or chemical plating to form a Ni plating layer, and then to electroplating or chemical plating. Au plating to form a finish plating layer. Thereafter, a water-repellent film 4 of alkoxysilane or silazane is formed on the surface of the glass 2 in the same manner as in the case of the matching sealing type. The change in the insulation resistance of the glass 2 after having been left under high-temperature and high-humidity conditions was measured for the water-repellent film 4 of alkoxysilane or silazane formed on the surface of the glass 2 of the hermetic terminal as described above. As a result, a result as shown in the graph of FIG. 4 was obtained. 4th
In the figure, Example 1 uses borosilicate glass as glass 2,
The water-repellent film 4 is made of dimethylmethoxysilane. In Example 2, borosilicate glass was used as the glass 2.
The water-repellent film 4 is formed of hexamethyldisilazane. Comparative Example 1 uses borosilicate glass as the glass 2;
No water-repellent film 4 was formed. Example 3 used soda barium glass as glass 2 and water-repellent film 4 was formed of dimethylmethoxysilane. Example 4 used soda barium glass as glass 2. The water-repellent film 4 is formed by using hexamethyldisilazane. Comparative Example 2 shows a case where soda barium glass is used as the glass 2 and the water-repellent film 4 is not formed. The water-repellent film 4 was formed by immersing the whole hermetic terminal in dimethylmethoxysilane or hexamethyldisilazane, pulling it up, and immediately heating it at 20 ° C. for 1 hour and drying it. The test is to measure the insulation resistance of the glass 2 of the airtight terminal before and after leaving it for 500 hours under high temperature and high humidity conditions of 40 ° C and 90% RH under the conditions of 25 ° C, 60% RH and 500V DC. Done by As shown in the graph of FIG. 4, a water-repellent film 4 of alkoxysilane or silazane
It is confirmed that the formation of the layer can significantly reduce the insulation resistance as compared with the case where the water-repellent film 4 is not formed. Further, the alkoxysilane or silazane forming the water-repellent film 4 does not generate a toxic gas such as chlorine gas, and has no risk of adversely affecting the human body and is easy to handle. Further, the alkoxysilane and the silazane do not volatilize even when heated to about 180 ° C., and there is no danger of contact failure due to volatilization of Si when an airtight terminal is used for a relay or the like. And when attaching the airtight terminal to electrical equipment such as a relay,
The soldering of the leads 3 and the welding of the metal outer ring 1 can be performed without causing a defect due to the water-repellent film 4 formed of alkoxysilane or silazane. Therefore, even if the water-repellent film 4 adheres to the exposed surface of the lead 3 or the exposed surface of the metal outer ring 1, there is no particular need to remove the water-repellent film 4 from these surfaces. Here, in order to solder the lead 3 and the metal outer ring 1 without removing the water-repellent film 4, it is necessary to apply a finish plating layer of Au plating to the lead 3 and the metal outer ring 1. When welding without removing the water-repellent film 4, it is preferable to perform laser welding. In the case of resistance welding, it is preferable to provide projections on a header or a case. When welding is performed by these methods, the water-repellent film 4 can be easily broken and reliable welding can be performed.

【The invention's effect】

As described above, in the present invention, after forming a finish plating on the metal outer ring and the lead by gold plating, forming a water-repellent film by applying alkoxysilane or silazane on the surface of the glass, the metal outer ring and the lead. Since the alkoxysilane or silazane does not generate toxic gas,
A water-repellent film can be formed without fear of affecting the human body.Also, without removing the water-repellent film with alkoxysilane or silazane, soldering or welding can be applied to the lead or metal outer ring that has been finished plated with gold plating. This can eliminate the need for an operation process for removing the water-repellent film from the surface of the lead or the metal outer ring.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment of the present invention, FIG. 2 is a block diagram showing a process of manufacturing a matched sealing type hermetic terminal according to the first embodiment,
FIG. 3 is a block diagram showing a process of manufacturing a compression-sealed hermetic terminal of the above, FIG. 4 is a graph showing a change in insulation resistance when glass is placed under high temperature and high humidity conditions, and FIG. It is a graph which shows the relationship between the surface resistivity of glass and humidity. 1 is a metal outer ring, 2 is glass, 3 is a lead, and 4 is a water-repellent film.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-51-97795 (JP, A) JP-A-60-221470 (JP, A) JP-A-2-247914 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H01R 43/20 H01R 9/16

Claims (1)

(57) [Claims] 1. A metal outer ring and a lead are hermetically and insulated and sealed via glass, and a finish plating is formed on the metal outer ring and the lead by gold plating. A method for producing a hermetic terminal, comprising forming a water-repellent film by applying alkoxysilane or silazane.