JPS61290673A - Airtight insulated terminal and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to an airtight insulated terminal used for electrically connecting an electrical device housed in a metal airtight container to the outside. Airtight Tik terminals used in forced cooling type rectifiers, etc., in which a liquid compound such as 70 liters is filled as a cooling medium in an airtight container, and a semiconductor rectifier for large currents is immersed inside the container. This relates to a manufacturing method.

[Prior art] The general characteristics required for this type of airtight insulated terminal are high heat resistance, no deterioration over time, and an extremely high degree of airtightness (watertightness).
properties, high corrosion resistance against cooling media, high thermal and mechanical shock resistance, and a terminal conductor (hereinafter referred to as
It has high insulation properties with respect to the conductive electrode (simply referred to as a "carrying electrode"). In addition, it is naturally required that the device be easily connected to the airtight container while maintaining airtightness, and be inexpensive.

Recently, the number of cases in which the rectifier is mounted on a vehicle as a power supply device is rapidly increasing, but in this case, it is essential to reduce the weight of the rectifier itself. Demand for airtight insulated terminals with light weight is rapidly increasing.

Conventionally, it has been known to use synthetic resin, rubber, glass, or porcelain materials as electrical insulators and airtight sealing materials for this type of hermetically insulated terminal, but there are also ones that use synthetic resin or rubber. has poor heat resistance properties and deteriorates over time, has unreliable air-tightness properties, and has many problems in terms of corrosion resistance against cooling media. On the other hand, those using glass or porcelain materials have excellent performance in terms of airtightness and corrosion resistance, but have poor thermal and mechanical impact resistance.
Therefore, when used in rectifiers mounted on vehicles, etc., they have a fatal defect of being damaged by vibration, making it impossible to use them.

In this regard, the airtight insulated terminal that uses glass and mica plastic as the electrical insulator and airtight sealing material that the present inventors have previously proposed has excellent characteristics with respect to the above-mentioned required general characteristics. However, it has the fatal flaw of being heavy.

Hereinafter, the structure and mechanism of a light, conventional airtight insulated terminal will be explained based on FIG. In the figure, (1) is the base that is airtightly connected to the airtight container, (lc) is the joint with the container, and (2)
is a conducting electrode, and (3) is an insulator.

The insulator (3) is a glass obtained by using a mixed powder of vitreous powder and mica powder as a raw material, heating the raw material to a temperature at which the vitreous material softens and flows under pressure, and then press-molding it in the heated state. It is a mica plastic body, and the gap (4) between the through hole of the base (1) and the conducting electrode (2) is formed using a special molding die.
The insulator (3c) protrudes from the through hole on the upper surface (1a) and lower surface (1b) of the base (1).

An insulator (
3m) and (3b) are respectively formed. Insulator(
3C) is the effect of the sealing material that maintains the insulation and airtightness of the base (1) and the conducting electrode (2), and
3b) is a substrate (1) which plays the role of maintaining the creeping insulation resistance of both substrates.It is necessary that the substrate (1) maintains corrosion resistance against the filling in the airtight container, such as fluorocarbons, and the atmosphere. Also, the thermal expansion coefficient used is greater than that of glass or mica plastic bodies at a temperature below the transposition temperature. This glass
It can be considered that the transition temperature of the mica plastic body is equivalent to that of the raw material glass. In addition, the coefficient of thermal expansion is largely controlled by the raw material glass, and its value is 9 to 12.
The 0-conducting electrode (2), which can be changed to a temperature of about 47° C., has the same corrosion resistance as the substrate (1), and the thermal expansion coefficient is smaller than that of glass or mica plastic.

As mentioned above, the coefficient of thermal expansion is important when selecting materials for the base (1), the conductive electrode (2), and the insulator (3).
This is to ensure airtightness, which is the most important characteristic for this type of airtight insulated terminal. Since the coefficient of thermal expansion is closely related to the airtightness, the reason for this will be explained below.The reason is closely related to the manufacturing method, so based on Figure 4,
First, I will explain the 1-cent method.

The molding die has a divided structure having a wall (5), a frame (6), a holding hole (7&) for holding the conducting electrode (2), and an insulator (3b) having a gap Fj (4a). Structure receiver (7
) and a through hole (8a) in the center that fits with the conducting electrode (2).
A pressurized metal (8) with four parts is used. Add water to the raw material powder to make it wet, and apply it to the wall (
5) Preformed body (9) formed into a cylindrical shape by crisscrossing so that it can be inserted into the interior, and then dried to remove moisture.
Process and use. As shown in FIG. 4(a), the molding die first consists of a wall (5), a frame (6) and a receiver (7).
), and the pressurized metal (8) is heated to a temperature higher than the transition temperature of the raw glass without being assembled. If the temperature is lower than the transition temperature, the heated preform (9) and When in contact, the raw material glass cools and solidifies, resulting in poor fluidity, making it difficult to form a high-density insulator (3), and conversely, if it is too high, the formed insulator (3) The primary substrate (1) and the conductive electrode (2) are heated to a higher temperature than the molding die.

The preform (9) is heated under pressure to a temperature at which it can flow. When each heating is completed, first the base (1)
and the conducting electrode (2) are inserted into the mold, and then the preform (
9) is placed on the base (1). This state is shown in Figure 4 (
The zero-order pressurized metal (8) shown in a) is molded into a preformed body (
9) and pressurize the pressurized metal (8) using a pressurized molding machine (not shown). The preform (9) flows by being pressurized, and part of it remains on the base (1), the other part fills the gaps (4) and (4a), and forms the insulators (3a) and (3b). )
, (3c) are constructed. This state is shown in FIG. 4(b). The formed insulator (3) can flow or deform under pressure in a temperature range higher than the transition temperature of the raw glass, but solidifies in a temperature range below the transition temperature.
The insulator (3c) existing in the gap (4) between the base (1) and the conducting electrode (2), which behaves as a solid,
) from the temperature at which it solidifies to room temperature, a large tightening pressure is applied toward the center due to the contraction of the base (1), which has a large coefficient of thermal expansion at the outer periphery. At the same time, insulators (3
) strongly compresses and tightens the conducting electrode (2), which is located in the center and has a small coefficient of thermal expansion. This phenomenon is very similar to the shrinkage phenomenon. Therefore, the compressive force generated on the inner and outer circumferential surfaces of the insulator (3), that is, the contact surface between the base (1) and the conducting electrode (2), ensures that the airtight insulated terminal maintains excellent airtightness.

In order to achieve the above-mentioned state, it is an essential condition that a tightening force is generated in the base (1), and if the yield strength of the base (1) is insufficient, the base (1) will become stretched. Tightening force is no longer generated. In order to prevent the elongated state from occurring, a material with a high yield strength, such as stainless steel, is used for the base body (1), but in order to ensure absolute yield strength, the thickness of the base body (1) has to be increased.

In conventional products, the base (1) is made of thick stainless steel.
Titanium, copal, or the like is used for the conducting electrode (2). In that case, the coefficient of thermal expansion of stainless steel is 18X 1
0-@/”C1 lath, mica plastic body is 9~12X 1
0-'/'C, titanium is 8 x 10-'/'C, and Kovar is 5 I was satisfied.

[Problems to be solved by the invention] However, as mentioned above, in the case of conventional products, the base (1) is made of stainless steel material with a high specific gravity, and thick parts are used, so the product There was a problem that the weight itself was heavy. This is a fatal flaw in applications that require light hermetically insulated terminals.

The present invention was made to solve these problems, and aims to provide a light airtight insulated terminal while maintaining the excellent characteristics of conventional products.

[Means for Solving the Problems] The present invention provides a base body having eleven through holes, the base body passing through the through hole while maintaining a gap with the peripheral wall, and having both ends protruding from both end surfaces of the base body. a conducting electrode, an insulator made of glass or mica plastic material forming a creeping insulation portion interposed in the gap, sealingly fixing the base body and the conducting electrode, and surrounding the circumferential surface of the conducting electrode protruding from the through hole; The present invention relates to an airtight insulated terminal having a glass film formed on the inner circumferential surface of the through hole of the base body, and a method for manufacturing the same.

[Example 1] In order to achieve the above-mentioned object, the present inventors first focused on a conventional airtight insulated terminal, and developed a product in which the thickness of the base body (1) was reduced to reduce the tightening force. was investigated in detail. As a result, there was no leakage phenomenon at the contact surface between the glass and the mica plastic body that constitute the conducting electrode (2) and the insulator (3c), and the glass and the mica plastic body themselves. It was confirmed that there was a leakage phenomenon only at the contact surface. By preventing leakage in this part, the above-mentioned objective was achieved.

The present invention will be explained based on FIGS. 1 and 2.

Figure w&1 is a vertical sectional view showing the structure of an embodiment of the present invention. The base body (1) has a thin wall, has a flange-shaped joint part (1d) with the metal container at the lower end, and has a glassy coating (10) on the inner circumferential surface of the through hole. During molding, as shown in Figure 2, an auxiliary wall (11) with a split structure surrounding the outer periphery of the base (1) is used, and this is placed on the brim-shaped joint (1d) of the base (1). and assembled to surround the base (1). After that, the auxiliary wall (11) is attached to the base (1).
and simultaneously inserted into the wall (5). Note that the conducting electrode (2) and preform (9) are the same as those used in conventional products.

Next, the most important element is the base with the hostage film (
1) will be explained next. The material used for the base body (1) is stainless steel, which has corrosion resistance and high yield strength.

First, it is necessary to form a film on the inner circumferential surface of the through hole of the base (1) without causing any cracks or nails to fly off, so the thermal expansion coefficient of the hostage film must be the same as that of the base (1).
and whose dislocation temperature is lower than the heating temperature of the preform (9).

In addition, to treat the inner peripheral surface of the through hole where the glassy film is to be provided, in order to improve the adhesion, sandblasting is performed to make the surface rough, or an oxide film is formed in advance by heating in the air or by chemical treatment. In that case, the coating is made by finely pulverizing the glass and making it into a slurry using water, etc., then making a coating by spraying or dipping, and then baking it in a furnace after drying. It is formed by

Among the molding conditions for the airtight insulated terminal of the present invention, the heating temperature of the mold and parts will be explained next. In the molding die, the wall (5), frame (6), receiver (7) and pressurizing metal (8) are heated to a temperature higher than the transition temperature of the raw material plus the auxiliary wall (11).
The substrate (1), which is assembled integrally with the through hole and has a glassy film formed on the inner circumferential surface of the through hole, is heated to a temperature higher than the transition temperature of the raw glass and the glassy material on which the film is formed, using a conductive electrode (2).
is the same temperature as or higher than the temperature of the molding die, and the temperature of the preform (9) is such that it can flow under pressure, and the temperature is higher than the transition temperature of the glass for the vitreous coating provided on the substrate (1). They are heated to high temperatures and molded using conventional products and a flattening process.

The preform (9) flows under pressure, and a portion of the preform (9) flows into the base (1).
) and the auxiliary wall (11), and the rest remain on the gap (4)
, (4a), and insulators (3a), (3b), (3
c). Figure 1 shows the disassembled mold after cooling.
FIG. 3 is a longitudinal sectional view of the airtight insulated terminal of the present invention obtained by removing the auxiliary wall (11).

In the airtight insulated terminal of the present invention, since the base body (1) has a thin wall thickness and poor proof strength, a tightening force against the insulator (3c) interposed in the internal gap (4) is hardly generated.

Therefore, unlike conventional terminals, it is not possible to maintain airtightness due to the tightening force, but the preformed body (9)
In the state where the substance (1) is fluidly filled, the hostage skin I! (10) and the temperature of the raw glass in the pre-11 molded body (9) are both in the temperature range higher than the transition temperature, so they fuse together, and as a result, they are integrated to maintain airtightness. The airtightness is ensured by a completely different configuration from conventional products. Next, the outer peripheral surface of the reverse electrode (2) and the insulator (3c)
The contact surface of the electrode (2) has a coefficient of thermal expansion opposite to that of the insulator (3c).
Since it is larger than that of the conventional product, it generates a tightening force and can maintain the same airtight properties as conventional products.

The above description of the present invention is based on the case where the glassy coating (10) is provided on the inner circumferential surface of the through hole of the base (1).
It is also possible to use a glass film formed on the outer peripheral surface of the counter electrode (2), and this can be effective depending on the shape.

Furthermore, although the description of the present invention is based on an airtight insulated terminal for a rectifier that uses liquid as a medium, the application of the present invention is not limited to this, and can also be used for metal containers filled with high-pressure gas. It is possible.

Furthermore, it can be used for airtight insulated terminals used in parts of space equipment, and its uses are extremely wide.

[Effects of the Invention] As explained above, the thickness of the base (1) of the present invention is thinner than that of conventional products, so that the present invention has the effect of significantly reducing its weight. At this time, the electrical properties including creeping insulation properties, mechanical and thermal shock strength, and corrosion resistance required for this type of product are the same as conventional products, and the technical and practical value is extremely high. It's a big thing.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view showing the structure of an embodiment of the airtight insulated terminal of the present invention, and Fig. 2 is an embodiment of the airtight insulated terminal of the invention [one child molding method] (&) indicates immediately before pressure forming. (b) is a vertical cross-sectional view showing the state after pressure forming is completed, and FIG. 3 is a vertical cross-sectional view showing the structure of an example of a conventional airtight insulated terminal.
Figure 4 shows an example of the conventional molding method for airtight insulated terminals (
, ) is a vertical cross-sectional view showing the state immediately before pressure forming, and FIG. 7(b) is a longitudinal sectional view showing the state after pressure forming is completed. In the figure, (1) is the base, (2) is the reverse electrode, (3) is the insulator, (5) is the wall, (6) is the frame, (7) is the receiver, (
8) is pressurized gold, (10) is a glassy film, and (11) is an auxiliary wall. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (4)

[Claims] (1) A base body having a through hole, a conductive electrode that penetrates the through hole while maintaining a gap with the peripheral wall, and is disposed with both ends protruding from both end surfaces of the base body, and a conductive electrode that is interposed in the gap and connects to the base body. In the airtight insulated terminal, the terminal is provided with an insulator made of glass or mica plastic material, which seals and fixes the conductive electrode and forms a creeping insulation portion surrounding the circumferential surface of the conductive electrode protruding from the through hole. An airtight insulated terminal characterized by a glassy film formed on the inner peripheral surface of the hole. (2) The airtight insulated terminal according to claim (1), which has a flange-like portion on one end surface of the base that does not form a glassy film. (3) The airtight insulated terminal according to claim (1) or (2), wherein the coefficient of thermal expansion of the glass or mica plastic body at temperatures below the transposition temperature is greater than that of the conductive electrode. (4) It has an outer mold having an inner diameter larger than the maximum diameter of the base body, and a holding hole whose outer diameter fits into the inner diameter of the outer mold and can hold a conducting electrode in the center, and a gap part which can constitute a creeping insulation part. A molding die comprising a split-structure receiver and an inner mold made of a pressurized metal whose outer diameter fits into the inner diameter of the outer mold and has a through hole in the center that fits into the conducting electrode. , and a step of forming a mixed powder constituting an insulator to prepare a preformed body by using an auxiliary wall of a split structure surrounding the base and having an outer diameter that fits into the inner diameter of the outer mold, and penetrating the base. The process of forming a glassy film on the inner peripheral surface of the hole, the process of inserting the holder into the external mold and heating it together with the pressurized metal to a temperature higher than the dislocation temperature of the raw material, and the process of forming an auxiliary wall on the outer periphery of the base. a step of heating the substrate with the auxiliary wall interposed therebetween to a temperature higher than the transition temperature of the glass on which the vitreous film is formed; a step of heating the conductive electrode to the same temperature or higher temperature than the mold; heating the preform to a temperature at which it can flow under pressure and which is higher than the transition temperature of the glass of the glassy film formed on the base; and heating the preform to a temperature that is higher than the transition temperature of the glass of the glassy film formed on the base. a step of inserting the base into the holding hole, a step of placing the base with the auxiliary wall interposed therebetween on the receiver, a step of placing the preform on the base, and a step of placing the pressurized metal on the preform. The process of pressurizing the preform through a pressurizing metal to form an insulator in the gap, disassembling the mold after cooling, and taking out the molded product.
A method of manufacturing an airtight insulated terminal comprising a step of removing an auxiliary wall.