JPS6166611A - Manufacture of tray for heating - 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 A. Field of Industrial Application The present invention relates to a heating tray (for example, a tray for firing ceramic electronic components) used when heat-treating an object to be heated with the object placed thereon. ).

In recent years, ceramics for electronic components have made remarkable progress.
Typical examples include ferromagnetic materials such as ferrite and ferroelectric materials such as barium titanate.

All of these are made by sintering molded products at high temperatures of over 1,200°C.In particular, recently developed high-performance products tend to be sintered at even higher temperatures; It is being done.

When sintering ceramics, the molded product is placed on a refractory tray and placed in a furnace to prevent deformation and ensure uniform heating. The problem in this case is the contact reaction between the ceramic and the tray. If a contact reaction occurs, the properties of ceramics will be extremely deteriorated, so in order to avoid the contact reaction, a method is generally adopted in which zirconia powder is used as a release agent.

Zirconia has extremely excellent properties as a neutral refractory, and has excellent chemical stability at high temperatures. Therefore, if zirconia powder is spread on the surface of a tray, and a ceramic molded product is placed on top of the zirconia powder and heated, no adhesive reaction will occur.

However, with this method, it is necessary to spread zirconia powder on the surface of the tray one by one, and it takes time to attach and detach the molded product. This is especially a problem when attaching and detaching the device automatically. Therefore, an attempt was made to make the tray itself from zirconia instead of using it as a release agent, but as is well known, pure z r O2
It is difficult to sinter because it undergoes a transformation with a volume change of about 9% at 1000°C, and the commonly found zirconia sintered crystals are stabilized zirconia made by adding a small amount of zirconia CaO or Y2O3 to reduce strain in the crystal lattice. The material is called. However, the above-mentioned stabilized zirconia is inferior in chemical stability to pure zirconia and is prone to catalytic reactions.

Furthermore, trays made of silicone material are heavy and have poor workability.

C. Purpose of the Invention As a tray and method for manufacturing the same that solves the problems of the conventional trays as described above, the applicant first proposed a tray with a heated object placed on it and a method for protruding the heated object from the tray. A tray for heating an object to be heated, characterized in that ceramic fine particles different from the substrate are fixed thereto, and a first step of adhering ceramic fine particles to an adhesive film provided on the mold surface of the mold material; A second step of injecting the base material into the mold surface, and a third step of solidifying and molding the base material.
and a fourth step of releasing the mold material so that the ceramic fine particles are held on the molded substrate side (particularly in the present invention). Application No. 57-231002).

The tray based on the above invention has complete corrosion resistance even after repeated use, and the ceramic fine particles do not peel off, and has extremely excellent durability.

An object of the present invention is to provide an improved method for manufacturing the tray according to the invention of Japanese Patent Application No. 57-231002.

2. Structure of the invention, that is, the present invention covers the mold surface of the model with a plastic film coated with an adhesive on at least one side, with the adhesive coated side facing up, and the air is removed between the model and the plastic film. a first step in which the plastic film is brought into close contact with the mold surface of the model by exhausting the plastic film toward the model; a second step in which refractory ceramic fine particles are adhered to the adhesive-coated surface of the plastic film; and a second step in which the plastic film is brought into close contact with the model. a third step of injecting a base material onto the plastic film which has been molded and has refractory ceramic fine particles attached to its surface; a fourth step of solidifying and molding the base material; and a fourth step of injecting the molded base material into the ceramic film. The method of manufacturing a heating tray includes a fifth step of firing after releasing the mold together with the fine particles from the model.

E. Examples The present invention will be described in detail below with reference to FIGS. 1 to 5.

First, as shown in FIG. 1, a model 1 equipped with an exhaust hole 2 penetrating from the mold surface to the back surface was placed on a box body 3 with an open upper side, and a mold (not shown) was placed on one side of the model 1. A plastic film 7 coated with an adhesive and having a thickness of 0.1 to 0.15 mm is placed over the plastic film 7 with the adhesive coated side facing up.

Next, as shown in FIG. 2, the air between the model 1 and the plastic film 7 is removed by the exhaust hole 2, the suction box 5 formed by the model 1 and the box body 3, and the box body 3. The plastic film 7 is brought into close contact with the mold surface of the model 1 by evacuating through the exhaust port 4 by an exhaust pump (not shown).

Next, as shown in FIG. 3, place the bottom 1! on the plastic film 7! Place the frame body 6 that I11 opens, spread the zirconia fine particles 9 of about 100 to 150 mesh on the plastic film 7, and after adhering the zirconia fine particles to the plastic film surface, turn it over and inject -8. is filled into the cavity formed by the model 1 and the frame 6. The refractory slurry 8 contains coarse grains and fine grains of mullite,
It is made by mixing silica sol with mullite powder and further adding a gelling promoter.

After the refractory slurry 8 has gelled and solidified to an extent that does not pose a problem in handling, the exhaust from the exhaust port 4 is stopped,
The model 1 is then released from the mold while introducing pressurized air from the exhaust port 4. This mold release can be performed extremely easily. Next, the frame 6
When removed, as shown in FIG. 4, a green tray 10 is obtained in which fine zirconia particles 9 are thinly adhered to the surface of the substrate which has been almost solidified for a day. Since the zirconia fine particles 9 are adhered to the surface of the plastic film 7 by the adhesive applied to the plastic film 7 attached to the green tray 10-1-, they are inside the green tray 10. It does not move and forms a thin layer with a uniform thickness.

Since the substrate 18 is not completely solidified, the green tray 10 is dried with the plastic film attached or after the plastic film is removed.
The tray 20 shown in FIG. 5 is produced by heating to 00° C. and firing.

The tray 20 thus obtained has a structure in which a thin layer of zirconia fine particles 9 is formed on the surface of a completely solidified base 28, and the surface of this thin layer is smooth. Moreover, since the base body 28 is made of mullite, it is lightweight.
The tray 20 has high mechanical strength and is resistant to thermal shock.

When the tray manufactured as described above was used in the actual manufacture of ceramic capacitors, etc., the zirconia surface thin layer had perfect corrosion resistance, and no peeling occurred due to repeated heating.

Note that providing a vent hole at the end of the mold surface side of the exhaust hole 2 shown in FIGS. 1 and 2 is effective in preventing the plastic film 7 from being drawn into the exhaust hole 2 during exhaust. It is.

Further, the model 1 and the box body 3 may be integrated to form the exhaust box 5 therein.

Furthermore, if high accuracy is not required for the thickness dimension of the tray, instead of the frame 6 shown in FIG. If you do this, the slurry pouring work will become simpler.

Furthermore, the plastic film 7 shown in FIG.
Preheating to a temperature of about 250°C to soften it is effective in preventing wrinkles from forming on the tray surface of the product. In this case, it is preferable to use a thermoplastic adhesive.

As described in detail, the tray manufacturing method of the present invention is simple to manufacture, and particularly easy to release from the mold, since it involves the steps described above. Moreover, the tray obtained by the method of the present invention has extremely good surface smoothness, corrosion resistance, peeling resistance, mechanical strength, and heat resistance, and has no concerns about durability. .

[Brief explanation of the drawing]

Figures 1 to 5 show an example of the tray mounting procedure according to the present invention. Figure 1 is a cross-sectional view showing the plastic film covered on the model, and Figure 2 is a cross-sectional view showing the plastic film tightly attached to the model. A cross-sectional view showing the state, a cross-sectional view showing the state where the rally is enlarged by 1L, Fig. 4 is a cross-sectional view showing the solidified tray molded product released from the model, and Fig. 5 is a cross-sectional view of the tray product. . In addition, regarding the symbols shown in the drawings, ■・・・・・・・・・・・・・・・・・・・・・・・・
Model 2・・・・・・・・・・・・・・・・・・・・・
・・Exhaust hole 3・・・・・・・・・・・・・・・・・・
・・・・・・Box 4・・・・・・・・・・・・・・・・・・
・・・・・・Exhaust port 5・・・・・・・・・・・・・・・
・・・・・・・・・Suction box 6・・・・・・・・・
・・・・・・・・・・・・・・・Frame 6a...
・・・・・・・・・・・・・・・・Refractory slurry injection lower・・・・・・・・・・・・・・・・・・・・・・・・・
・Plastic film 8・・・・・・・・・・・・・・・
・・・・・・・・・Refractory slurry 9・・・・・・
・・・・・・・・・・・・・・・・・・ Zirconia fine particles 10・・・・・・・・・・・・・・・・・・・・・
...Green tray 18...
......Gelified base 28...
・・・・・・・・・・・・・・・・・・・Completely solidified base 20・・・・・・・・・・・・・・・・・・・
...It is a tray product. Agent: Patent Attorney Hiroshi AisakaFigure 1Figure 2

Claims (1)

[Claims] 1. Cover the mold surface of the model with a plastic film coated with adhesive on at least one side, with the adhesive coated side facing up,
A first step of evacuating the air between the model and the plastic film to the model side and bringing the plastic film into close contact with the mold surface of the model; and applying refractory ceramic fine particles to the adhesive-coated surface of the plastic film. a second step of adhering the base material; a third step of injecting the base material onto the plastic film that is in close contact with the model and having refractory ceramic fine particles adhered to the surface; and a third step of solidifying and molding the base material. A method for manufacturing a heating tray comprising four steps and a fifth step of releasing the molded base together with the ceramic fine particles from the model and then firing.