JPS6050335B2 - heat treatment jig - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in heat treatment jigs, particularly in sealing jigs for hermetic terminals.

There are various types of airtight terminals depending on the purpose, etc., but the most typical one is a cylindrical metal outer ring 1 with a glass 2 in between, as shown in Figure 1. 3 sealed in an airtight and insulating manner.

Such an airtight terminal is manufactured using a sealing jig 4 made of graphite as shown in FIG.

In the figure, reference numeral 5 denotes a jig main body, which has a recess 6 at the upper end in which the metal outer ring 1 can be accommodated, and an insertion hole 7 for the lead wire 3 formed at the center of the bottom surface of the recess 6. Reference numeral 8 denotes a bottom plate, which is fixedly integrated with the jig main body 5 by means of graphite pins (not shown).

The metal outer ring 1 is inserted into the recess 6, the cylindrical glass tablet 20 is inserted into the metal outer ring 1, and the lead wire 3 is inserted into the center hole 21 of the glass tablet 20. In this state, the whole is heated to about 100°C in a neutral or weakly reducing atmosphere. Then, glass tablet 2
0 is melted and the lead wire 3 is hermetically and insulatively sealed through the glass 2, thereby obtaining an airtight terminal as shown in FIG. By the way, this type of sealing jig 4 is manufactured by carving a recess 6 and a lead wire insertion hole 7 in a graphite block made by compression molding carbon powder. When inserting or removing the lead wire 3 from the lead wire insertion hole 7, as shown in FIG.
Also, the inner surface of the lead wire insertion hole 7, especially the upper shoulder part, is severely worn, and after several times of use, when the metal outer ring 1 and the lead wire 3 are inserted, these may become eccentric or the glass tablet 20 may become uneven. When melted, the lead wire 3 is inclined, making it impossible to obtain an airtight terminal with the desired dimensional accuracy.

In addition, graphite grains that have fallen off from the sealing jig 4 are caught in the molten glass, causing damage to the metal outer ring 1 and the lead wire 3.
When finishing plating is applied to the glass surface, the plating tends to stick to the graphite grains that are caught on the glass surface.
Furthermore, carbon liberated from the sealing jig 4 penetrates into the grain boundaries of the metal outer ring 1 and the lead wires 3. Due to the so-called carburizing phenomenon, the properties of the metal outer ring 1 and lead wire 3 change,
Plating non-adherence and plating unevenness are likely to occur during the final plating. In addition, the oxide film formed on the surface of the metal outer ring 1 and the lead wire 3 reacts with carbon to form carbide and adheres to the sealing jig, and the carbide is removed from the glass sealing process several times later. There have been various problems such as the so-called transfer phenomenon that occurs when the metal re-adheres to the metal outer ring 1 and the lead wire 3, causing non-adhesion or uneven plating during final plating. Therefore, the main object of the present invention is to provide a heat treatment jig, such as a sealing jig for an airtight terminal, which is less abrasive and has a longer service life.

To summarize, the present invention is characterized in that at least the metal outer ring and the parts of the lead wires that come into contact with the parts to be processed are made of boron nitride.

The above-mentioned objects and other objects and features of the present invention will become more apparent from the detailed description of the invention with reference to the drawings.

FIG. 4 shows a sectional view of the present invention applied to a hermetic terminal sealing jig similar to that shown in FIG. 2.

In the figure, 40 is a sealing jig with a jig main body 41 and a bottom plate 45.
It is composed of The jig main body 41 has a recess 42 formed of graphite and into which the metal outer ring 1 can be inserted;
Lead wire insertion hole 4 formed at the center of the bottom surface of this recess 42
3, and a boron nitride layer 44 is formed on the entire surface thereof. The bottom plate 45 is also made of graphite, and a boron nitride layer 46 is formed on the entire surface thereof. According to the above configuration, since the boron nitride layers 44 and 46 are formed on the entire surface of the jig main body 41 and the bottom plate 45 made of graphite, when the metal outer ring 1 is inserted into and removed from the recess 42 and when the lead wire insertion hole 43 The recess 4 when the lead wire 3 is inserted or removed from the
2 and the inner surface of the lead wire insertion hole 43 is significantly reduced, and the sealing jig 40 can be used for a long period of time.
Not only is the cost of the sealing jig for each airtight terminal reduced, resulting in a reduction in cost, but also problems such as staining of the glass surface due to graphite powder and adhesion of plating are eliminated, and a high-quality airtight terminal can be obtained.

Next, a method for manufacturing the sealing jig 40 according to the present invention will be explained.

First, a jig main body 41 having 200 recesses 42 and lead wire insertion holes 43 is manufactured by cutting a graphite block having a length of 100 wrm, a width of 50, and a thickness of approximately 8 w0n. Further, the bottom plate 45 is manufactured by cutting a graphite plate having a thickness of about 5 Trr1n into the same dimensions as described above. On the other hand, an aqueous solution was prepared in which boron nitride powder with an average particle size of about 1.4 to 1μ was suspended at a concentration of 0.5 to 20%.
The jig main body 41 and the bottom plate 45 are immersed for 1 to 3 minutes,
After lifting, the temperature is 100-3000C and the temperature is 60-12
By drying, boron nitride layers 44 and 46 having a thickness of about 1 to 10 μm were formed on the entire surface of the jig main body 41 and the bottom plate 45. Thereafter, the jig main body 41 and the bottom plate 45 were combined and integrated using pins (not shown) to produce the sealing jig 40. Using the above sealing jig 40, the outer diameter is 377!
117! φ, inner diameter 2Tf0! A metal outer ring 1 made of Kovar (Fe●Ni●CO alloy) with lφ and height of 1.5Twt,
A sintered glass with an outer diameter of 2mm is made by kneading fine powder of borosilicate glass with an organic binder, press-molding it into a cylindrical shape, and then calcining it at about 700°C to burn out the organic binder. Glass tablet 20 with φ, inner diameter 0.5TVLφ, height 1.5T1$&, outer diameter 0.5TrrInφ, length 10T! Rl
Assemble the lead wire 3 made of n Kovar in a predetermined position and heat it to 950 to 10 in a neutral or weakly reducing atmosphere.
The glass tablet 20 was melted by heating at 50° C. for 10 to 20 minutes to produce an airtight terminal as shown in FIG.

When the sealing jig 4 was repeatedly used to manufacture airtight terminals as described above, the dimensional accuracy of the airtight terminals began to deteriorate due to wear of the sealing jig 40, but approximately It was the 200th time.

Furthermore, due to the boron nitride layers 44 and 46, carbon released from the jig main body 41 and the bottom plate 45 penetrates into the grain boundaries of the metal outer ring 1 and lead wires 3.
The so-called carburization phenomenon, in which the properties of the steel change, can be prevented. Further, the oxide film formed on the surface of the metal outer ring 1 and the lead wire 3 turns into carbide and adheres to the sealing jig 40, and this carbide re-adheres to the other metal outer ring 1, lead wire 3, or glass 2. , the so-called carbide transfer phenomenon did not occur. On the other hand, using a conventional sealing jig 4 that combines a jig main body 5 and a bottom plate 8 that have the same shape and dimensions as the sealing jig 40 and do not have the boron nitride layers 44 and 46, When an airtight terminal was manufactured under the same conditions as above, the dimensional accuracy became incorrect after about 120 times.

In addition, defects such as non-adherence or plating on the metal outer ring 1 or lead wire 3 due to carburization caused by free carbon from the sealing jig 4 or transfer of carbide, or plating adhesion to the surface of the glass 2 may occur. 15% hot. In the above embodiment, a case has been described in which the jig main body 41 and the bottom plate 45 are immersed in an aqueous solution in which fine boron nitride powder is suspended to form boron nitride layers 44 and 46 on the entire surface. It may be formed only on the inner surfaces of at least the recess 42 and the lead wire insertion hole 443 by spraying or applying.

If necessary, the entire sealing jig 40 may be constructed of boron nitride. Furthermore, the present invention can be applied not only to sealing jigs for airtight terminals but also to other heat treatment jigs.

As described above, in this invention, since at least the part that comes into contact with the parts to be treated is made of boron nitride, not only the service life of the heat treatment jig is significantly increased, but also the carburization phenomenon due to free carbon and the transfer due to peeled carbide are achieved. This phenomenon is eliminated, and the effect is that Kyoto-grade heat treatment can be performed.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of a typical airtight terminal, Fig. 2 is a cross-sectional view showing the assembled state before glass sealing to explain the conventional manufacturing method of the airtight terminal shown in Fig. 1, and Fig. 3 is a sectional view of a typical airtight terminal. FIG. 4 is a cross-sectional view showing the assembled state before glass sealing when the fitting jig is worn out. FIG. 4 is a cross-sectional view of a sealing jig for an airtight terminal according to an embodiment of the present invention. 40...Heat treatment jig (sealing jig), 41...Jig body, 42...Recess, 43...Lead wire insertion hole, 44, 46...・Layer of boron nitride, 45・
·····Bottom plate.

Claims (1)

[Scope of Claims] 1. A heat treatment jig comprising boron nitride at least in the portion that contacts the part to be treated. 2. The heat treatment jig according to claim 1, which is made of graphite and has a boron nitride layer formed on its surface.