JPH07120162A - Multistage kiln and pressurizing baking method using it - Google Patents

Abstract

PURPOSE:To remove bubbles, so as to obtain a firmly sintered body by providing filling recessed parts into which baking bodies are filled on the upper surfaces of a plurality of press boards in a kiln, and providing pressurizing projecting parts to be matched to the filling recessed parts on the lower surface, and moving respective press boards in the alternate vertical directions. CONSTITUTION:A press board stand 1 provided with a plurality of step parts la is arranged in a furnace. Press boards 2, 3 having the size to be matched to respective step parts 1a are placed thereon, and a plurality of filling recessed parts 2a, 3a are formed on the upper part. Pressurizing projecting parts 3b to be respectively matched to the filling recessed parts 2a, 3a are provided on the lower part of the press board 3 other than that on the lowermost stage. Moreover, the press board 2 on the lowermost stage is supported by vertically moving shafts 6a and supported on a fixed stand 8 so as to be vertically moved by a moving mechanism 7. Thereby, bubbles can be removed by pressing all press boards 2, 3 from above and from beneath by the moving stand 6 and a fixed plate 5 provided above press board 3 on the uppermost stage, thereby a firmly sintered body can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a firing furnace for ceramics used in semiconductor packages, ceramic substrates for various electronic parts, parts for industrial machines, cutting tools and the like, and a firing method using the same.

[0002]

2. Description of the Related Art Generally, ceramics are obtained by molding raw material powder into a predetermined shape by a method such as press molding and sintering it in a firing furnace. It is important to And
It is known that by firing the molded body while pressurizing it rather than under normal pressure, the effect of removing the above-mentioned pores is large and the mechanical properties and the like of the obtained ceramics can be improved.

As this pressure firing method, a hot press (uniaxial pressure) method, a HIP (hot isostatic pressure) method and the like are used.

[0004]

The hot pressing method is a method in which a carbon material installed in a firing furnace is filled with a ceramic raw material powder and fired while applying pressure from above and below, but the firing capacity is small and continuous. Since it is difficult to use, a large amount of products cannot be fired, which is not suitable for mass production.

Further, the HIP method has a problem that the apparatus is extremely large, the work is complicated, and the cost is high.

[0006] Therefore, an object of the present invention is to provide a firing furnace and a firing method for performing pressure firing which enables mass production at low cost.

[0007]

In view of the above, the present invention provides:
A plurality of press plates are installed side by side in the vertical direction inside a baking furnace, and a filling recess for filling the baked product is provided on the upper surface of each press plate, and a pressing protrusion having a shape matching the filling recess is provided on the lower surface. And a means for moving each press platen in the up-and-down direction of each other to constitute a multi-stage firing furnace.

Further, according to the present invention, after filling the filling concave portion with a firing material such as a ceramic raw material or a ceramic compact by using the above-mentioned multi-stage firing furnace, each press plate is combined with the filling concave portion and the pressing convex portion. It is moved so as to be pressed in the vertical direction, and firing is performed in a pressurized state.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

The multi-stage firing furnace shown in FIG. 1 comprises a heater 11 inside a heat insulating member 10 to form a furnace. Inside the furnace, a step-type press board base 1 is arranged, the press board base 1 is provided with a plurality of step portions 1a, and each step portion 1a has a size that exactly matches each step portion 1a. Press boards 2 and 3 are mounted. Further, each press platen 2, 3 has a plurality of filling recesses 2a, 3a in the upper part, and the filling recesses 2a, 3a are respectively provided in the lower part of the press platen 3 other than the lowermost stage.
The pressure protrusion 3b having a shape matching a is provided.

Further, the lowermost press board 2 is supported by a vertically movable shaft 6a of a movable table 6, and the movable table 6 can be moved vertically on a fixed table 8 by a movable mechanism 7 utilizing a hydraulic press or the like. Supported by. Further, a fixed plate 5 is provided on the upper part of the uppermost press board 3, and a pressurizing convex portion 5a having a shape matching each filling concave portion 3a is provided on the lower surface thereof. It should be noted that the press board 1 and the press boards 2 and 3 are
Is made of carbon or ceramics having excellent heat resistance.

When performing pressure firing using this multi-stage firing furnace, first, the filling recesses 2a, 3a of the press machines 2, 3 are
After filling the fired material 4 such as the ceramic raw material powder or the ceramic molded body, the movable table 6 is moved upward by the movable mechanism 7. Then, the lowermost press platen 2 is pushed up by the vertically movable shaft 6a, and the pressurizing convex part 3b of the upper press platen 3 enters into the filling concave part 2a of this press platen 2 and the upper side of the baked product 4 is pressed. The press board 3 will also be pushed up. In this way, the press plates 3 are pushed up one after another, and finally, as shown in FIG. 2, all the press plates 2 and 3 are pressed by the movable table 6 and the fixed plate 5 from above and below.

At this time, the pressurizing projections 3b of the upper press board 3 enter the filling recesses 2a, 3a, so that the baked product 4 filled in the filling recesses 2a, 3a is pressed. Then, if the inside of the furnace is heated by the heater 11 and fired in this state, each fired product 4 is fired in a pressurized state. Obtainable.

After the firing, the movable table 6 may be lowered to the state shown in FIG. 1 and the fired body may be taken out from the filling recesses 2a, 3a.

In such a multi-stage firing furnace of the present invention, a plurality of press plates 2 and 3 are provided with a large number of filling recesses 2a and 3a, and a large number of fired products 4 can be simultaneously pressure-fired.
It is possible to perform pressure firing that enables mass production at low cost. In particular, it can be suitably used for firing ceramic substrates for semiconductor packages and electronic parts, zirconia sheets for fuel cells, cutting tools, and other ceramic parts for industrial machines.

Further, in the above embodiment, each press board 2, 3 is used.
Although the example in which the pressure is applied from only the lower side is shown, the structure can be applied from the upper side or from both the upper and lower sides. Further, the means for moving the press boards 2 and 3 is not limited to the one using the movable table 6 and the movable mechanism 7 shown in the above embodiment, and various other mechanisms may be used.

The multi-stage firing furnace of the present invention can be used for normal pressure firing without pressurizing, or can be used for preliminary firing at a temperature lower than the original firing temperature.

Example Here, the zirconia sheet was actually fired using the multi-stage firing furnace shown in FIGS. The size of the heat insulating member is 1 width
000 mm, depth 1000 mm, height 800 mm, each filling recess 2a is filled with a zirconia green sheet, the pressurizing pressure is 800 kg / cm ² , and the firing temperature is 1500 ° C. and the holding time at that temperature is 2 hours. Baked.

It has been confirmed that the zirconia sheet obtained by this method is superior in mechanical properties such as hardness and strength to those obtained by the conventional firing method in which pressure is not applied.

[0020]

As described above, according to the present invention, a plurality of press plates are movably installed side by side in the vertical direction in the firing furnace, and the upper surface of each press plate is provided with a concave portion for filling the burned material with the lower surface. Is equipped with a pressurizing convex portion having a shape matching the filling concave portion, and is equipped with a means for moving each press platen in the vertical direction to form a multi-stage firing furnace. By firing under pressure, bubbles can be removed and a dense sintered body can be obtained. Further, since a large number of fired products can be fired at the same time, labor saving of work and significant cost reduction can be achieved.

[Brief description of drawings]

FIG. 1 is a sectional view showing a multi-stage firing furnace of the present invention.

FIG. 2 is a cross-sectional view showing a pressurized state of the multi-stage firing furnace of the present invention.

[Explanation of symbols]

 1: Press platen 2, 3: Press platen 4: Burned product 5: Fixed plate 6: Movable table 7: Movable mechanism 8: Fixed table 10: Thermal insulation member 11: Heater

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area C04B 35/64 C04B 35/64 J

Claims (2)

[Claims] 1. A plurality of press plates are movably installed side by side in a vertical direction in a firing furnace, and a recess for filling a fired product is formed on the upper surface of each press plate, and the filling recess is formed on the lower surface. A multi-stage firing furnace having means for moving each press platen in the vertical direction, each having a pressurizing convex portion having a shape. 2. A plurality of press plates are movably installed side by side in a vertical direction in a firing furnace, and a filling recess is formed on the upper surface of each press plate, and a pressing protrusion having a shape matching the filling recess is formed on the lower surface. Using a firing furnace equipped with each section, after filling the filling concave portion with the baked material, each press platen is moved vertically so as to press the pressing convex portion and the filling concave portion in combination with each other, and the pressure is applied. A pressure firing method comprising a step of firing in a state.