JPH10335041A - Manufacture of air-tight terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an air-tight terminal, which can secure the air-tight adhesion strength at the time of glass sealing and in which adhesion of glass grains to a lead wire is prevented, by pressing a surface of the glass fused in an envelope metal body with an end surface of a projection, which is provided with a small hole for insertion of a set lead wire and a space in the periphery thereof. SOLUTION: An envelope metal body 3 is arranged in a support base 6 on a base 5, and two lead wires 4 and the granular glass material 1 are set in the envelope metal body 3. They are put in a heating furnace so as to fuse the glass material 1. A surface of the glass 2 is pushed by an end surface of a projection 9 of a pushing means 8. This projection 9 is provided with a small hole for insertion of the lead wires 4, and has a space 14 between the outer peripheral surface thereof and the inner wall of the envelope metal body 3. At this stage, outer diameter of the projection 9 is represented by (a), lead wire diameter is by ϕ, pitch between the lead wires is by (p), inner diameter of the envelope metal body 3 is by (b) so as to satisfy a formula b>a>=ϕ+ρ, desirably so as to satisfy an expression a≈ϕ+ρ. With this structure, adhesion of glass grains to the lead wires 4 is prevented, and the inner surface of the envelope main body is formed with a glass swelling part 21, and glass sealing is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the field of manufacturing technology of hermetic terminals.

[0002]

2. Description of the Related Art A conventional technique for manufacturing a hermetic terminal will be described with reference to FIG.

FIG. 2 is an explanatory view showing a conventional method of manufacturing a general hermetic terminal. FIG. 2A shows three types of hermetic terminals using three types of heat-resistant jigs. 1 is a glass material, 3 is a shell-shaped surrounding metal body serving as a case of an airtight terminal, 4 is a lead wire, 5
Is a base, 6 is a support for the surrounding metal body, 7 is an upper plate jig, 10
Is space.

FIG. 2B is a cross-sectional view showing a state in which the glass material 1 is heated and softened. FIG. 2B shows glass, and FIG. 2C shows welding of the glass 2 to the surrounding metal body 3. FIG. 4D is a cross-sectional view showing the state, and FIG. 4D is a perspective view of the hermetic terminal taken out of the jig after glass sealing.

In the cross-sectional view of FIG. 2A, the surrounding metal body 3 is supported and defined by the surrounding metal body 3 placed on the base 5, and two lead wires serving as electrodes are provided. 4 and 4, and the glass material 1 are set in a predetermined shape, and the upper plate jig 7 is further placed thereon and heated in a neutral atmosphere furnace set to at least the melting temperature of the glass of the glass material 1. The lead wires 4 and 4 are insulated and hermetically sealed to the surrounding metal body 3 through glass, and thus, as shown in FIG.
The airtight terminal shown in the perspective view of FIG.

The surrounding metal body 3 and the lead wires 4, 4 are
Both are made of Fe-Ni-Co alloys, and their surfaces are made of Fe
-An oxide film of a Ni-Co alloy is formed.

The glass material 1 is made of borosilicate glass having a coefficient of thermal expansion matching that of the surrounding metal body 3 and the lead wire 4. The glass material 1 is formed into a button-shaped tablet in advance so that it can be easily used as an assembly part. What is hardened by sintering is used.

The heat-resistant jig is usually formed in a multi-piece structure so that several hundred hermetic terminals can be manufactured at one time.

[0009]

In the conventional method for manufacturing a hermetic terminal as described above, as shown in the perspective view of FIG. 2D, the glass of the lead wire 4 of the hermetic terminal after sealing is applied. In many cases, small glass particles 22 are attached to a close portion.

If such glass particles 22 adhere to the lead wire 4, plating such as gold plating or preliminary solder plating applied in a finishing surface treatment in a later step is not applied thereto or peels off later. Therefore, an early solution has been desired from the viewpoint of quality assurance of the hermetic terminal.

Then, when the cause of such adhesion of glass particles was investigated, when the glass material 1 began to soften at the temperature in the heating furnace (about 700 ° C.), as shown in the sectional view of FIG. The glass 2 is first welded to the lead wire 4 via the oxide film of the lead wire 4, and as the temperature rises, the viscosity of the glass decreases, as shown in the sectional view of FIG. The glass melts and flows and fuses to the inner wall surface of the surrounding metal body 3, but at this time, the glass welded to the lead wire 4 does not completely flow into the inside of the surrounding metal body 3 and a part of the lead wire 4, the residual glass is spheroidized by surface tension, becomes glass particles 22 and adheres to the lead wire 4, and such a phenomenon is caused by the upper plate jig 7.
It was found to be caused by the space 10 between the glass material 1 and the glass material 1.

Therefore, as a method of removing this cause,
When the glass material 1 starts to soften in the heating furnace, as shown in FIG.
In order to prevent the glass from being wetted and welded to the external lead wire via the oxide film on the surface of the lead wire 4 as described above, it was conceived to press the surface of the glass near the lead wire 4 with a jig.

In order to form the entire surface of the glass portion of the hermetic terminal flat by the method of processing the hermetic terminal, a method of holding the entire glass portion with a jig is disclosed in Japanese Patent Publication No. 51-3787.
No. 9 discloses this.

That is, as shown in the cross-sectional views of FIGS. 3 (a) and 3 (b), the gist of the invention is that "a pressing member (pressing means 12) made of carbon having a flat portion joined to the molten glass surface. This is a method of processing a base in which the surface of a molten glass (glass 2) is pressed and the molten glass is formed into a flat surface over the entire surface in a concave portion of a base plate (surrounding metal body 3).

That is, conventionally, the size a of the outer diameter of the protrusion 11 is substantially the same as the inner diameter b of the surrounding metal body 3, and is a size obtained by adding the diameter φ of the lead wire 4 and the pitch p between the lead wires 4. It is much larger than that, that is, it has the following relationship.

B ≒ a> φ + p Accordingly, the pressing element for forming the molten glass into a flat surface over the entire surface in the recess of the surrounding metal body 3, that is, the diameter of the inner peripheral surface of the surrounding metal body 3 When the glass part is pressed by a pressing means 12 provided with a projection 11 having an end surface having substantially the same diameter as that of the inner wall surface of the surrounding metal body 3 of the glass 2 part as shown in the perspective view of FIG. The sealing path of the glass is shortened, so the sealing strength decreases by that much,
This is not preferable for a hermetic terminal.

Particularly, in recent years, since the size of the electronic component has been reduced, the surrounding metal body has also become smaller, and securing a sealing path has become the most important matter. Therefore, this processing method cannot be applied.

The present invention has been made to solve the above-mentioned problems, and its object is to
It is an object of the present invention to provide a method of manufacturing a hermetic terminal that secures hermetic sealing strength without shortening a glass sealing path on an inner wall surface of an outer metal body and has no glass particles attached to a lead wire.

[0019]

According to a method of manufacturing an airtight terminal of the present invention, an end surface of a projection formed at a predetermined position of a pressing means and provided with a small hole through which a plurality of lead wires are passed is formed by forming an outer metal body. A method of sealing a glass by pressing at least a surface portion of the glass which is wetted to an external lead wire which is not glass-sealed of a lead wire without pressing a surface portion of the glass which is wetted to an inner wall surface, wherein When the diameter is a, the lead wire diameter is φ, the pitch between the lead wires of the airtight terminal is p, and the inner diameter of the surrounding metal body is b, the following conditions are satisfied.

B> a ≧ φ + p or a ≒ φ + p

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the method for manufacturing a hermetic terminal according to the present invention will be specifically described with reference to examples.

[0022]

1 (a) to 1 (d) show an embodiment of a method for manufacturing a hermetic terminal according to the present invention.

FIG. 1A is a cross-sectional view of a state in which three types of members constituting a hermetic terminal are assembled using three types of heat-resistant jigs made of carbon. 4 is a lead, 5 is a base, 6 is a support for the surrounding metal body, 8 is pressing means, 9 is a protrusion, and 14 is a space.

When the inner diameter b of the surrounding metal body 3 is, for example, 3.8 mm, the wire diameter φ of the lead wire 4 is selected to be 0.47 mm, and both are made of an Fe—Ni—Co alloy commonly called Kovar. In addition, an oxide film of Kovar is formed on each surface by a high-temperature oxidation treatment in advance so as to improve the familiarity with glass.

The glass material 1 is made of borosilicate glass having a thermal expansion coefficient equal to that of Kovar, and is formed into a button shape by powder molding and sintering so that it can be easily handled as an assembled part.
The diameter of the glass material 1 is 3.65 mm.

The pressing means 8 is provided with a cylindrical projection 9 at a predetermined position. The height h of the projection 9 is 0.3 mm, and the outer diameter a of the end face is 3.2 mm.

Further, the pressing means 8 is provided with two holes, each having a diameter d of 0.5 mm, through which the two lead wires 4 are passed at predetermined positions and having a diameter d of 0.5 mm.

The jigs are formed in a multi-piece structure so that about 170 hermetic terminals can be formed at one time.

FIG. 1B is a cross-sectional view showing a state of the glass material 1 after softening by heating, 2 is glass, and FIG.
FIG. 4D is a cross-sectional view showing a state after glass melting, and FIG. 4D is a perspective view of an airtight terminal taken out of a jig after glass sealing.

In FIG. 1A, the surrounding metal body 3, two lead wires 4, and the glass material 1 are set in a predetermined shape in a support 6 for the surrounding metal body. Glass material 1
The pressing means 8 is placed with the end face of the projection 9 in contact with the holes for the lead wires 4 and 4 on the surface of.

Then, the assembly is heated in a neutral atmosphere furnace of nitrogen gas set at about 1000 ° C., and the end surface of the projection 9 presses the glass surface close to the lead wire 4 to the external lead wire. Of the molten glass is prevented, and the two lead wires 4, 4 are insulated and hermetically sealed to the surrounding metal body 3 via the glass.

What is particularly important here is that the projection 9 does not press the entire surface of the glass but presses the glass surface in a portion close to the lead wire 4.

At this time, the outer diameter a of the end face of the cylindrical projection 9 is 3.2 mm, the diameter φ of the lead wire 4 is 0.47 mm, the pitch p between the two lead wires 4 and 4 is 2.54 mm, and The inner diameter b of the surrounding metal body 3 is set to 3.8 mm.

That is, the following relationship is established. b (3.8)> a (3.2)> φ (0.47) + p
(2.54) For this reason, even if the glass starts to soften, as shown in FIG. 1B, the protrusion 9 of the pressing means 8 presses the glass surface around the lead wires 4, 4. The glass is not welded to the outside of the surroundings 4 and 4. Further, at the time of melting the glass, when the glass is pressed into the surrounding metal body 3 at the end face of the projection 9 as shown in FIG. Since it is easy to move to the direction of the space 14 having the width e without pressing, it moves to the inside of the recess of the surrounding metal body, and is wetted and sealed by the oxide film on the inner wall surface of the surrounding metal body. In addition to securing a deposition path, the glass does not wet outside the lead wires 4 and 4, and glass particle adhesion does not occur.

In the case of multi-cavity production, even if the weight of each glass material varies, it is adjusted by the presence of the unpressed space 14 so that the airtight terminal can be manufactured without being affected by the difference in the weight of the glass material. There is also an effect that can be done.

In this embodiment, the diameter d of the lead wire penetrating hole of the cylindrical projection 9 is 0.4 mm of the lead wire diameter φ.
0.5 mm compared to 7 mm, but as close as possible to the lead wire diameter φ within the range of ease of insertion of the lead wire during assembly to prevent the glass from climbing into the gap between the lead wire It is desirable to set the dimensions.

In the present embodiment, the outer diameter a of the end surface of the cylindrical projection 9 is set to 3.2 mm, which is 3.8 mm of the inner diameter b of the outer metal body 3. The width e of the space 14, that is, “(ba) / 2” is made as large as possible so as not to prevent the glass crawling up so as not to shorten the glass sealing path necessary for keeping the airtight and wet.
The outer diameter a is the sum of the lead wire diameter φ and the lead wire pitch p “φ +
It is desirable to set the dimension value as close as possible to "p" and as far as possible from the inner diameter b of the surrounding metal body 3, that is, the following relationship.

A ≒ φ + p When a is equal to “φ + p” or slightly smaller than “φ + p”, that is, when a = φ + p or a <φ + p, the lead wire extends from the wall surface of the protrusion. Although the hole is visible, even in such a case, if a part of the end surface of the projection is caught on the external lead wire and a part of the glass is pressed, it will be held down because the glass is viscous. Glass that is not entangled is restrained from creeping up, thereby preventing glass particles from adhering to external lead wires.

Therefore, the present invention is not necessarily limited to “a> φ + p”.

[0040]

As described above, according to the method for manufacturing a hermetic terminal according to the present invention, the end surface of the projection provided on the pressing means presses the glass surface near the lead wire during heating and melts the external lead wire. Since the glass is prevented from adhering and the lead wire is insulated and hermetically sealed to the surrounding metal body via the glass, the sealing path on the inner wall surface of the surrounding metal body after sealing is not reduced. In addition to ensuring a predetermined glass sealing strength, it is possible to significantly reduce the adhesion of glass particles to the lead wires and to provide a high-quality hermetic terminal. There is also an effect that terminals can be manufactured.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a method of manufacturing a hermetic terminal according to an embodiment of the present invention. (A) Cross-sectional view of a state in which a member of an hermetic terminal is incorporated in a heat-resistant jig. Sectional view showing state after (c) Sectional view showing state after melting of glass (d) Perspective view of airtight terminal taken out from jig after glass sealing

FIG. 2 is an explanatory view showing a conventional general method for manufacturing a hermetic terminal; (a) a cross-sectional view in which a member of the hermetic terminal is incorporated in a heat-resistant jig; (b) a glass material after being softened by heating. Sectional view showing state (c) Sectional view showing state of glass after welding (d) Perspective view of airtight terminal taken out of jig after glass sealing

FIG. 3 is an explanatory view showing a method of manufacturing a conventional hermetic terminal of the entire glass part pressing type. (A) Cross-sectional view of a state in which a member of the hermetic terminal is incorporated in a heat-resistant jig. (B) Immediately after glass sealing Sectional view showing state (c) Perspective view of airtight terminal taken out of jig after glass sealing

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Glass material 2 Glass 3 Surrounding metal body 4 Lead wire 5 Base 6 Support for surrounding metal body 8 Pressing means 9 Projection 14 Space 21 Glass crawling up part 22 Glass grain

Claims (3)

[Claims] A support for supporting and defining an outer metal body of a hermetic terminal is arranged, and the outer metal body, and at least two lead wires and a glass material are set on the support base in a predetermined shape. An assembly comprising pressing means for pressing the glass material is passed through a heating furnace to melt the glass material, and the lead wire is insulated and hermetically sealed to the surrounding metal body via the glass. In the method for manufacturing a hermetic terminal, the glass formed at a predetermined position of the pressing means and having a small hole through which a plurality of lead wires are provided is wetted at least on the inner wall surface of the surrounding metal body at the end face. Without pressing the surface of
A method for manufacturing a hermetic terminal, comprising pressing and sealing a surface portion of glass which is wetted to an external lead wire portion of the lead wire which is not sealed with glass. 2. When the outer diameter of the projection is a, the diameter of the lead wire is φ, the pitch between the lead wires is p, and the inner diameter of the surrounding metal body is b, the following conditions are satisfied. Item 7. A method for manufacturing a hermetic terminal according to Item 1. b> a ≧ φ + p 3. The method for manufacturing an airtight terminal according to claim 1, wherein the following conditions are satisfied when the outer diameter of the projection is a, the lead wire diameter is φ, and the pitch between the lead wires is p. . a ≒ φ + p