JPH0547322A - Lead sealing stem - Google Patents

Abstract

PURPOSE:To facilitate manufacture, reduce the cost, and prevent the occurrence of oxidation, discoloration, and rust on the surface of an eyelet and a lead. CONSTITUTION:A lead 12 is sealed to an eyelet 10 in insulation via glass 14, and low-melting point glass 16 for sealing is sealed to the eyelet 10. A corrosion- resistant plated film 22 is formed on the eyelet 10 and the lead 12, and the low-melting point glass 16 is sealed to the eyelet 10 via the corrosion-resistant plated film 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead sealing stem suitable for use in a viewfinder cathode ray tube stem or the like.

[0002]

2. Description of the Related Art A viewfinder cathode ray tube stem hermetically seals an electron gun of a cathode ray tube and insulates leads for external extraction with glass, and has a structure as shown in FIG. Eggplant An eyelet 10 is made of an iron-based material such as 426 alloy (iron-nickel-chromium alloy). A lead 12 is insulated from the eyelet 10 by the glass 14 and sealed. Reference numeral 16 is a low-melting glass, which is sealed to the eyelet 10 via an oxide film 18. The low melting point glass 16 is for hermetically sealing the tube 20 of the electron gun.

[0003]

In the method of manufacturing such a stem, an oxide film is first formed on the eyelet 10 and the lead 12 in order to obtain a strong adhesiveness between metal and glass. Eyelet 1 by glass 14 through
After the 0 and the lead 12 are insulated and sealed, the low melting point glass is sealed to the eyelet 10 in the following complicated process. That is, since the oxide film is reduced and drops in the glass 14 sealing step (electric furnace), the oxide film for sealing the low melting point glass 16 needs to be formed again. Therefore, after acid treatment, an oxide film is formed on the entire exposed portions of the eyelet 10 and the leads 12, and then the low melting point glass 16
In order to leave an oxide film only on the sealing part of the glass, a resist is applied to the sealing part to selectively remove the oxide film on other parts, and then the resist is peeled off to form a low melting point glass on the sealing part. And apply
It was necessary to carry out complicated and multi-steps of heating to remove the binder and further heating to glaze. As a result of performing the above multi-steps, there is a problem that the cost becomes high. In addition, since the metal is exposed on the outer surfaces of the eyelet 10 and the leads 12, there is a problem that oxidation, discoloration, and rust easily occur. Corrosion-resistant plating may be applied to the exposed parts of the eyelets 10 and leads 12, but the low-melting-point glass component is eluted into the plating solution and the plating solution is contaminated. There may be a problem with the stopping property.

Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to facilitate the production and reduce the cost, and to oxidize, discolor, and rust the surface of the eyelet and the lead. It is an object of the present invention to provide a lead sealing stem capable of preventing the above.

[0005]

The present invention has the following constitution in order to achieve the above object. That is, in the lead sealing stem in which the eyelets are insulated and sealed with glass by the glass, and the low-melting glass for sealing is sealed in the eyelets, a corrosion-resistant plating film is formed on the eyelets and the leads. A low melting point glass is sealed to the eyelet through the corrosion resistant plating film. It is preferable that the low melting point glass contains lead oxide as a main component, and the corrosion-resistant plating film is an electrolytic nickel plating film, an electroless nickel-boron plating film, or an electroless nickel-phosphorus plating film.

[0006]

In the past, the adhesion between metal and glass was poor. Therefore, in order to improve the adhesion, it is general that an oxide film is formed on the metal and the glass is adhered through this oxide film. Was required. As a result of a study by the inventor, it is true that in the case of a glass having a silicic acid content as a main component such as borosilicate glass, the direct adhesive force with a metal was low, but a low-melting point glass lowers its melting point so that lead oxide Is as high as 75% to 80%, and a high content of this metal component is considered to enhance the adhesive force with the metal, and the adhesive strength of the low melting point glass 16 to the corrosion-resistant plating film 12 can be sufficiently satisfied. It was a thing. It is considered that this adhesive force is due to the anchor effect due to the rough surface of the plating film and the formation of a certain strong intermetallic compound between the metal of the plating film and lead in the low melting point glass. Incidentally, the eutectic temperature of nickel and lead is 324 ° C.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows a sectional view of a lead sealing stem, and the same members as those of the stem shown in FIG. The characteristic point of this embodiment is that the eyelet 10,
An anticorrosion plating film 22 is formed on the leads 12, and the low melting point glass 16 is inserted through the anticorrosion plating film 22 to form the eyelet 1
It is sealed at 0. The corrosion-resistant plating film 22 is
The electrolytic nickel plating film, the electroless nickel-boron plating film, and the electroless nickel-phosphorus plating film are preferable, but the electrolytic nickel plating film is particularly preferable in terms of corrosion resistance and adhesion strength with the low melting point glass 16. ..

The stem is manufactured as follows. First, an oxide film is formed on the outer surfaces of the eyelet 10 and the lead 12, and then the eyelet 10, the lead 12 and the glass tablet are mounted on a jig and placed in an electric furnace to melt the glass and insert the glass through the oxide film. The point that the eyelet 10 and the lead 12 are insulated and sealed by 14 is the same as the conventional one.
The oxide film is reduced in the sealing process with the glass 14 in the electric furnace, and the oxide film on the exposed portion of the eyelet 10 and the lead 12 is removed. Next, after pretreatment, a corrosion resistant plating film 22 is formed on the exposed portions of the eyelet 10 and the leads 12. When the corrosion-resistant plating film is an electrolytic nickel film, the eyelet 10 and the leads 12 are appropriately electrically connected. The thickness of the corrosion resistant plating film 22 is not particularly limited, but about 2 to 4 μm is sufficient. Next, the low melting point glass 16 is applied to the sealing portion, heated to about 300 ° C. to volatilize the organic binder in the low melting point glass 16, and then heated to about 500 ° C. to glaze the low melting point glass 16. Obtain the desired stem.

As the low-melting glass 16, known glass having lead oxide as a main component can be used. Low melting point glass 1
6 is a low melting point glass which is obtained by adding an appropriate organic binder to a low melting point glass powder and molding it into a desired shape by a powder molding method, and then heating it at 450 ° C. to 500 ° C. in the air to volatilize the organic binder and to glaze it. You may use the sintered body of. The glaze of the low melting point glass is preferably performed by heating to about 500 ° C. in a non-oxidizing atmosphere such as N ₂ gas. When the stem is for a viewfinder CRT, glaze treatment in vacuum is preferable.

Conventionally, the adhesion between metal and glass is poor, and therefore, in order to improve the adhesion, it is general that an oxide film is formed on the metal and the glass is adhered through this oxide film. Was required. As a result of a study by the inventor, it is true that in the case of a glass having a silicic acid content as a main component such as borosilicate glass, the direct adhesive force with a metal was low, but a low-melting point glass lowers its melting point so that lead oxide Is as high as 75% to 80%, and a high content of this metal component is considered to enhance the adhesive force with the metal, and the adhesive strength of the low melting point glass 16 to the corrosion-resistant plating film 12 can be sufficiently satisfied. It was a thing. It is considered that this adhesive force is due to the anchor effect due to the rough surface of the plating film and the formation of a certain strong intermetallic compound between the metal of the plating film and lead in the low melting point glass. Incidentally, the eutectic temperature of nickel and lead is 324 ° C.

3 to 9 show the results of testing the adhesive strength of the low melting point glass to the oxide film and various corrosion resistant plating films. The test method is to form an oxide film or a corrosion-resistant plating film on a metal plate made of iron-nickel-cobalt alloy,
A sample obtained by welding plate glass to this metal plate with low melting glass was fixed on the plate glass side to a jig of a tester, and the metal plate side was pulled in a direction parallel to the surface to examine the adhesive strength. Table 1 shows the processing conditions of each sample.

[0012]

[Table 1]

As is clear from FIGS. 3 to 9, in the case of Samples E to G shown in FIGS. 7 to 9 in which the plate glass is welded on the corrosion-resistant plating film by the low melting point glass, on another oxide film or The adhesive strength is higher than in the case of Samples A to D shown in FIGS. 3 to 6 directly welded on the metal surface. Particularly, in the case of sample G shown in FIG. 9 in which the electrolytic nickel plating film was formed, the adhesive strength was remarkably excellent.
It is considered that this is because the electrolytically plated film has a rougher surface condition than the electroless plated film, so that the anchor effect becomes larger.

Looking at the state of separation between the metal plate and the plate glass, in the case where the corrosion resistant plating film was formed, the low melting point glass remained on the corrosion resistant plating film side and was broken at the low melting point glass portion. From this, it can be seen that the adhesion strength of the low melting point glass to the corrosion resistant plating film is high. On the other hand, in the case where the oxide film was formed, the oxide film was removed from the surface of the metal plate. Although it can be said that the low-melting-point glass has a high adhesive strength with respect to the oxide film, it is considered that the oxide film itself is destroyed and eventually the adhesive strength of the plate glass is lowered. This can be understood from the fact that the plate glass directly welded to the surface of the metal plate by the low-melting glass has a slightly higher adhesive strength than the one formed with the oxide film. In Table 2, a sample in which the stem shown in FIG. 1 is capped with low-melting glass 16 is prepared, the sample is heated on a heat column, and the airtightness is investigated with a He leak detector. Shows the data for.

[0015]

[Table 2] The corrosion-resistant plating in the examples was electroless nickel-boron plating. In the above-mentioned embodiment, the stem for the viewfinder cathode ray tube has been described, but it can be suitably applied to a hermetic glass terminal for a semiconductor device which is mounted with a semiconductor chip and hermetically sealed with a cap using a low melting point glass. .. Although the present invention has been variously described with reference to the preferred embodiments, the present invention is not limited to these embodiments, and many modifications can be made without departing from the spirit of the invention. ..

[0016]

According to the lead sealing stem of the present invention, since the low melting point glass is sealed to the eyelet through the corrosion-resistant plating film, the manufacturing process can be simplified, and the low cost glass can be provided at a low cost. The melting point glass and the eyelet are firmly adhered to each other and have excellent airtightness. Moreover, since the corrosion-resistant plating film is formed on the exposed portions of the eyelets and leads, the corrosion resistance is also excellent.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a viewfinder CRT stem.

FIG. 2 is a sectional view of a conventional viewfinder CRT stem.

FIG. 3 is a graph showing the adhesive strength of sample A.

FIG. 4 is a graph showing the adhesive strength of sample B.

FIG. 5 is a graph showing the adhesive strength of sample C.

FIG. 6 is a graph showing the adhesive strength of sample D.

FIG. 7 is a graph showing the adhesive strength of sample E.

FIG. 8 is a graph showing the adhesive strength of sample F.

FIG. 9 is a graph showing the adhesive strength of sample G.

[Explanation of symbols]

 10 Eyelet 12 Lead 14 Glass 16 Low melting point glass 22 Corrosion resistant plating film

Claims (2)

[Claims] 1. In a lead-sealing stem in which a lead is insulated from an eyelet by glass and sealed, and a low-melting glass for sealing is sealed in the eyelet, a corrosion-resistant plating film is formed on the eyelet and the lead. Was
A lead sealing stem, wherein the low-melting glass is sealed to the eyelet via the corrosion-resistant plating film. 2. The low melting glass contains lead oxide as a main component, and the corrosion-resistant plating film is an electrolytic nickel plating film.
An electroless nickel-boron plating film or an electroless nickel-phosphorus plating film.
The described lead sealing stem.