JPS62242788A - Baking vessel - 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 This invention relates to an improvement in a firing container used for firing electronic industrial parts such as ferrite, capacitors, and phosphor powders.

WJL Flame 1 Conventionally, when electronic industry parts such as Ferrite I-, capacitors, and phosphor powders are heat-treated, a firing vessel has generally been used. Place the object to be fired inside the firing container, for example 12
The object to be fired was heat-treated at a high temperature of 00 to 1400°C.

The material for such firing containers was generally quartz glass.

However, quartz glass has the disadvantage that it devitrifies due to the halogen gas released when firing fluorescent materials. Therefore, the firing container made of quartz glass can only be used 10 to 20 times.

Therefore, Si 3 N4 Bonded 3i
Firing containers made of carbon and recrystallized SiC have come into use. However, Si 3 N
4 3onded St C firing containers not only have purity problems, but also easily oxidize, and are susceptible to creep deformation and cracking due to the SiO2 phase generated by oxidation and the glass phase contained within itself. tended to occur.

In addition, due to the manufacturing process, a firing container made of recrystallized SiC with high purity has 15 to 20% pores, and oxidizing gases enter the structure through the pores, causing oxidation of the silicon carbide itself. Similar to 3i 3 N4 [3onded si C], creep deformation and cracking tended to occur. Furthermore, materials such as Sl 3 N 4 3onded Si C have low thermal conductivity, which causes problems in uniform heat treatment of objects to be fired, and is a major factor in reducing yield during firing.

The object of the present invention is to eliminate the drawbacks of the prior art as described above, and to provide a firing container that takes measures against creep deformation, cracking, and uniform heating during use.

RJL PJLL In order to achieve the above-mentioned object, this invention uses ferrite,
In a firing container used for firing electronic industrial parts such as capacitors and phosphor powders, the firing container has a connective tissue made of silicon carbide and an aluminum (1!)-based or boron (B)-based sintering aid. The gist is a firing container that is characterized by:

8 - A firing container used when firing various electronic industrial parts, which creates a connective tissue using silicon carbide and aluminum (AQ)-based or boron (B)-based sintering aids.゛. Preferably, the firing vessel has an air permeability of 3.7X 100-3
Cm Q/c m23ecCm (underwater) or less. By the way, a conventional firing container made of recrystallized silicon carbide has an air permeability of 7 x 10-3 (, + ta Q /cm
It is about 23cccm.

Now, to explain the reason for creating a connective structure using silicon carbide and the sintering aid mentioned above, the problem with the conventional technology is that J: deformation occurs in the glass phase generated by oxidation or the glass phase 5iOz contained in itself. This may have caused cracking phenomena. Furthermore, in the case of quartz glass, there was a problem of devitrification.

Therefore, this invention creates a dense silicon carbide substance, a so-called self-sintering silicon carbide body, by adding a specific sintering aid to silicon carbide, and applies it to various electronic industry parts to achieve remarkable results. It is effective.

By creating a self-sintered body using silicon carbide and the specific sintering aid mentioned above, a dense connective structure without a glass phase is obtained, which not only prevents creep deformation but also cracking phenomena. I'm trying to do that.

A slip for casting was prepared by mixing 961 parts of Chisashi JLL SiC powder, 1 part by weight of 84C as a sintering aid, and 3 parts by weight of carbon black as a carbon source, and using water as a dispersion medium.

Further, Na 2 Si 03 was added as a deflocculant in an amount of 0.3% by weight. Such a slip is poured into a mold, shaped, demolded, and then sintered at 2180°C in an inert atmosphere (e.g. argon gas) to form a vertical
A firing container measuring 0 m+a, width 2801, and height 1401 was obtained.

On the other hand, for a comparative experiment, a firing container having the same shape and dimensions as the above-mentioned firing container was also made of another material.

Table 1 shows the experimental results of various such firing containers.

To explain the experimental conditions in Table 1, the firing temperature was 120
The process was carried out at 0°C using a continuous pusher in cycles of 15 hours/time, and the atmosphere was an oxidizing atmosphere (for example, ∆ir).
The material to be fired was a halophosphoric acid phosphor powder. The service life shown in the table is the average service life of five firing containers.

An experiment was conducted to compare the yield of the fired material between a firing container prototyped under the same conditions as in Example 1 and a firing container made of other materials. The results of the comparative experiment are shown in Table 2.

The yield values in Table 2 are the average values obtained from 50 experiments per container.

As is clear from Table 2, it was found that when the firing container according to the present invention was used, the yield of the fired products was improved by 1].

When considering how to improve the yield of the object to be fired in this way, we found that if the thermal conductivity is poor, such as in conventional firing containers, the center of the object tends to be underfired, and as a result, the yield decreases. is thought to have decreased. On the other hand, in the present invention, since an aluminum-based or boron-based sintering aid is used, the thermal conductivity of the firing container is 65 W/m'', which is very good, and the entire object to be fired is It is easy to be fired effectively.

Conventional Si 3 N 4 Bonded Si C (
The thermal conductivity of D is 18 W/m', and that of recrystallized SiC is 30 W/Ill'', and the firing vessel according to the present invention has a thermal conductivity of about 2 to 3 times. , it was possible to avoid uneven firing of the object to be fired, which resulted in a significant improvement in yield.

Table 1 Type Durability Remarks Si 3 N4 Bonded Si C103')'
) -7 Deformation/1ilJtL Recrystallized Si C386 Cracking Invention Product 1220 Cracking Table 2

Claims (1)

[Claims] A firing container used for firing electronic industrial parts such as ferrite, capacitors, and phosphor powder, wherein the firing container is made of silicon carbide and aluminum (Al)-based or boron (B)-based sintered material. A firing container characterized by having a connective tissue formed by an auxiliary agent.