JPH0812447A - Production of ceramic electronic part - Google Patents

Abstract

PURPOSE:To surely carry out defatting regardless of amounts and kinds of ceramic raw materials charged into a furnace by judging a point of time when defatting step in baking of raw ceramic material body is finished by measurement of change in oxygen concentration in the furnace. CONSTITUTION:In this method for producing ceramic electronic parts comprising baking raw ceramic element body by a defatting step and the successive main baking step, confirmation that debinding reaction in the defatting step is completely finished is carried out by measuring the change in oxygen concentration in the furnace. Thereby, it is not required to set the time for defatting step longer and baking time can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a ceramic electronic component, and more particularly to improvement of a firing process.

[0002]

2. Description of the Related Art In manufacturing a ceramic electronic component, a raw ceramic body is fired. This firing step has a degreasing step and a subsequent main firing step. In the degreasing step, the binder contained in the raw ceramic body is removed, that is, the binder is removed. Is sintered.

[0003]

In the above-mentioned degreasing step, it is important that the binder removal reaction is sufficiently completed. Because, if the binder removal is insufficient, the binder in the ceramic body is brought into the main firing stage as residual carbon, and if it is co-fired with the ceramic body, it may cause oversintering of the internal electrodes, for example. Because it does. In this way, when the internal electrodes become over-sintered, defects such as holes are formed in the internal electrodes.For example, in the case of monolithic ceramic capacitors, the capacitance falls below the design value, or in extreme cases. Causes a defect that no capacitance can be obtained at all.

As described above, the tendency that the binder removal ends inadequately appears more frequently particularly in the firing process of the ceramic electronic component using the base metal as the internal electrode. This is because in such a case, the amount of oxygen supplied in the firing step must be limited in order to suppress the oxidation of the base metal.

Generally, the conditions of the degreasing step are determined by the temperature and the time, and the temperature and the time are set empirically so that the debindering is sufficiently performed. However, even if the temperature and time are applied according to the set conditions, the furnace used may be changed, or the same furnace may be used for each firing batch or each time the amount or type of the ceramic body to be charged changes. In some cases, the binder removal reaction may be insufficient.

[0006] Therefore, it is an object of the present invention to provide a method for manufacturing a ceramic electronic component, which can ensure that the binder is always sufficiently removed.

[0007]

The present invention is directed to a method of manufacturing a ceramic electronic component, which comprises a step of firing a raw ceramic body in a furnace in a degreasing step and a subsequent firing step. In order to solve the above-mentioned technical problem, it is characterized in that the completion of the binder removal reaction in the degreasing step is confirmed by measuring the change in oxygen concentration in the furnace.

[0008]

The present invention was made by paying attention to the fact that the change in the oxygen concentration in the furnace has a correlation with the end of the binder removal. As described above, by measuring the change in the oxygen concentration in the furnace, it is possible to surely grasp that the binder removal reaction has been completed.

[0009]

Therefore, according to the present invention, it is possible to prevent the debinding process in the degreasing step from entering the main firing step with insufficient debinding reaction, so that the internal electrode is prevented from being over-sintered by residual carbon, for example. it can. Therefore, when the present invention is applied, for example, to the manufacture of a monolithic ceramic capacitor, it is possible to prevent the occurrence of a defect in which the electrostatic capacitance is below the designed value or the electrostatic capacitance cannot be obtained.

Further, when the binder removal reaction is completed by changing the furnace used in the firing process, changing the amount of the ceramic body loaded in the furnace, changing the type of the ceramic body, or for each firing batch. Even when fluctuates, the end time of such binder removal reaction can be surely grasped. Therefore, it is not necessary to set a long time for the degreasing step, and the minimum necessary time for degreasing can be set in the degreasing step, and as a result, the firing time can be shortened.

[0011]

EXAMPLE FIG. 1 shows the temperature profile set in the furnace during the degreasing step included in the firing process. On the basis of such a temperature profile, degreasing was performed on a raw ceramic body for a monolithic ceramic capacitor using a base metal as an internal electrode in an oxygen-limited atmosphere. As shown in FIG. Various changes in oxygen concentration were confirmed in the furnace.

As shown in FIG. 1, the oxygen concentration in the furnace first decreases as the temperature in the furnace rises. Here, it is considered that the binder removal reaction is in progress. While the temperature in the furnace reaches about 400 ° C. and is maintained at that temperature, the oxygen concentration in the furnace gradually rises, and then the point at which this rising tendency is saturated is reached. It can be judged that this time point is the time point when the degreasing is completed, or at least the time point when the binder removal reaction is sufficiently completed.

Therefore, immediately after the completion of the degreasing, the temperature in the furnace can be further raised and the firing step can be advanced to the main firing step so that the internal electrodes are sintered and the ceramics are sintered.

In this way, by measuring the change in the oxygen concentration in the furnace, the end point of the binder removal reaction can be confirmed regardless of the amount of the ceramic body loaded in the furnace and the type of the ceramic body. Therefore, after the degreasing step is completed, the step can be immediately transferred to the main firing step, and the time of the firing process as a whole can be shortened.

The present invention is not limited to the above-mentioned multilayer ceramic capacitor, but can be applied to all ceramic electronic parts having internal electrodes such as a multilayer circuit board, and further to ceramic parts not having internal electrodes. .

The present invention is particularly advantageously applied to a method for producing a ceramic electronic component in which a firing step is carried out in a batch furnace, and in particular, a ceramic electronic component fired in an atmosphere in which oxygen supply is restricted. Can be advantageously applied to the manufacturing method of.

[Brief description of drawings]

FIG. 1 is a diagram showing a relationship between a change in a furnace temperature and a change in a furnace oxygen concentration in a degreasing step according to an embodiment of the present invention.

Claims (1)

[Claims] 1. A raw ceramic body in a furnace,
In the method for manufacturing a ceramic electronic component, which comprises a step of firing in a degreasing step and a subsequent firing step, a confirmation that the debindering reaction in the degreasing step is sufficiently completed is made by changing the oxygen concentration in the furnace. A method for manufacturing a ceramic electronic component, which is performed by measuring.