JPH02145483A - Production of sintered aln - Google Patents

Abstract

PURPOSE:To improve the thermal conductivity and releasability of sintered AlN while preventing the mutual sticking of the sintered materials by stacking a plurality of formed AlN articles interposing sintered AlN powder between the articles and calcining the articles in nitrogen atmosphere. CONSTITUTION:Sintered powder is produced by calcining high-purity AlN powder in nitrogen atmosphere and subjecting the calcined powder to cooling, crushing and grading. A plurality of formed AlN articles are stacked one upon another interposing the above sintered powder between the articles and calcined in nitrogen atmosphere.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for producing an AIN sintered body, and more specifically, to a method for preventing AIN sintered bodies from sticking together during firing. The present invention relates to a method for producing an AIN sintered body.

(Prior art) The conventional method for producing an AIN sintered body is to first add and mix Y2O3 as a sintering aid to A1N powder, then add an organic binder and granulate it, and then press mold to produce an AIN compact. do. The AIN molded bodies were stacked in a firing container and fired in a nitrogen atmosphere to produce an AIN sintered body.

By the way, the reason for adding a sintering aid in the manufacturing process of AIN sintered bodies is that the sintering aid reacts with impurity oxygen in the AIN powder during the sintering process to form a liquid phase and promote sintering. At the same time, this is to trap impurity oxygen. In addition, since the liquid phase is discharged to the outside during sintering, the amount of liquid phase existing at the grain boundaries decreases, and the concentration of impurity oxygen within the grains decreases by preventing the solid solution of impurity oxygen within the grains. It has the effect of lowering In other words, by adding the sintering aid, an AIN sintered body containing less impurity oxygen and having high thermal conductivity can be obtained.

←Problems with the prior art) However, in the method for manufacturing AIN sintered bodies as described above, the AIN compacts stacked in the container do not become AI after sintering.
When the N sintered bodies were formed, the liquid phase discharged to the outside caused the AIN sintered bodies to stick together.

This stuck AIN sintered body is difficult to peel off in the conventional process using an ultrasonic cleaning machine, so it must be done manually, and there are many sintered bodies that cannot be peeled off, which is costly. This was the cause of the increase.

In addition, in order to prevent AIN sintered bodies from sticking together,
It has been considered to stack AIN compacts with conventionally used sintered powder such as Al2O3 and fire them, but this would result in poor peelability between the AIN sintered compacts and would not be suitable as a sintered powder. It was not put into practical use.

Therefore, the present invention is an attempt to solve the above-mentioned problems, and an object of the present invention is to provide a method for manufacturing an AIN sintered body that prevents the AIN sintered body from sticking together and has excellent thermal conductivity. It is.

(Means for solving the problem) The method for manufacturing an AIN sintered body of the present invention includes
Prepare a plurality of AIN molded bodies mainly composed of A
It is characterized in that IN molded bodies are stacked with sintered powder made of AIN powder interposed therebetween and fired in a nitrogen atmosphere.

(Function) According to the method for producing an AIN sintered body of the present invention, the AIN compacts are piled up with the sintered powder made of AIN powder interposed therebetween and fired.
The peelability between sintered bodies is improved.

(Example) Below, the method for manufacturing an AIN sintered body of the present invention will be described in detail.

First, high-purity AIN powder (for example, F type manufactured by Tokuyama Soda) was placed in an AIN crucible or carbon sac, and fired at 1800° C. for 8 hours in a nitrogen atmosphere. After cooling, it was crushed and sized to obtain a sintered powder.

Next, 100 wt% of high purity AIN powder (e.g. F type manufactured by Tokuyama Soda) was added, and 3% of Y2O3 was added as a sintering aid.
After adding wt% and mixing in toluene, an organic binder was added and mixed, and the slurry was evaporated, dried, and sized. Then, using this sized granule raw material in a mold, it can be directly processed!
Press-molded into a disc shape of 12 mm and 5 mm thick, and
A molded body was obtained.

Next, this AIN molded body was stacked in a firing container with sintered powder interposed therebetween, and fired at 1850° C. for 5 hours in a nitrogen atmosphere to obtain an AIN sintered body. On the other hand, as a comparative example, AI
A N sintered body was obtained.

Next, each AIN sintered body was taken out from the container and subjected to a peeling process. In this peeling step, the AIN sintered body of the present invention fired using the sintered powder was easily peeled off using a weak external force such as an ultrasonic cleaner. On the other hand, in the comparative example which was fired without using sintered powder, it was possible to peel it off manually, but it was difficult to peel it off using an ultrasonic cleaner.

In the above embodiment, the sintered powder was made of AIN, but next, in addition to the sintered powder made of AIN, Al2O3°BNy S 13N4? Peelability of AIN sintered body produced using as sintered powder,
The thermal conductivity was measured and the results are shown in Table 1.

Note that "O" in Table 1 indicates that the AIN sintered bodies are slightly attached to each other after firing, but can be peeled off by a weak external force such as ultrasonic cleaning.

"○" in Table 1 indicates that peeling is difficult with external force such as ultrasonic cleaning, but can be easily peeled off manually. The "x" in Table 1 indicates that manual peeling is also extremely difficult.

Table 1 As is clear from this Table 1, A as a sintered powder
AIN with excellent peelability and thermal conductivity when using IN
A sintered body can be obtained.

(Effects of the Invention) As explained above, according to the method for manufacturing an AIN sintered body of the present invention, even if the liquid phase is discharged to the outside of the AIN sintered body,
The presence of the sintered powder can prevent the AIN sintered bodies from sticking to each other, making it possible to obtain an AIN sintered body with excellent thermal conductivity.

Moreover, since the peeling process can be performed by ultrasonic cleaning, workability can be improved and costs can be reduced.

Claims (1)

[Claims] Manufacture of an AIN sintered body, characterized in that a plurality of AIN molded bodies mainly made of AIN are prepared in advance, the AIN molded bodies are stacked with sintered powder made of AIN powder interposed therebetween, and fired in a nitrogen atmosphere. Method.