JP2002156187A - Continuous baking furnace for baking unsintered material of ceramic electronic component and manufacturing method for ceramic electronic component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To supply atmospheric gas to an unsintered material of a ceramic electronic component more sufficiently and more uniformly when the unsintered material is baked in a continuous baking furnace. SOLUTION: Baffles 18 are so disposed as to be moved from the upstream and downstream sides in the direction of carriage in a carrying course 12, holding setters 14 accommodating the unsintered materials of the ceramic electronic components between them, or baffles 21 are provided fixedly in the vicinity of gas introduction ports 16 introducing the atmospheric gas. Thereby the atmospheric gas is directed forcibly in the direction of the setters 14 whereon the unsintered materials to be baked are disposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous firing furnace used for firing an unsintered ceramic electronic component,
And a method of manufacturing a ceramic electronic component using the same, and particularly, in a firing step performed when manufacturing a ceramic electronic component, an atmosphere gas to a ceramic electronic component green body as an object to be fired. The present invention relates to an improvement for achieving a uniform supply of the gas.

[0002]

FIG. 6 shows a conventional continuous firing furnace 1 which is of interest to the present invention. In FIG.
(1) is a plan view showing a part of the continuous firing furnace 1,
(2) is a sectional view of the continuous firing furnace 1. FIG.
In (1), the continuous firing furnace 1 is shown with its upper wall removed.

[0003] The continuous firing furnace 1 is also called a tunnel furnace or the like, and has a transfer path 2 through which a ceramic electronic component green body (not shown) to be fired is transferred. A plurality of transport base plates 3 are arranged in a row along the transport path 2, and these transport base plates 3 are moved along the transport path 2 during the firing process.

[0004] A plurality of setters 4 made of, for example, alumina are stacked on each transport base plate 3. The setters 4 form a space 5 between each other. The ceramic electronic component green body to be fired is placed on each setter 4. The space 5 between the adjacent setters 4 enables an ambient gas to be supplied toward the ceramic electronic component green body.

[0005] The continuous firing furnace 1 is also provided with a gas inlet 6 for introducing atmospheric gas into the furnace. The plurality of gas inlets 6 are located on the side wall 8 of the continuous firing furnace 1 so as to face each other across the setter 4 and to be distributed along the transport path 2. The atmospheric gas introduced from the gas inlet 6 is diffused throughout the furnace as indicated by the arrow 7.

[0006]

As described above, the atmospheric gas introduced into the furnace through the gas inlet 6 is supplied to the other furnaces before being supplied into the space 5 between the stacked setters 4. In some cases, the supply to the unsintered ceramic electronic component as an object to be fired on the setter 4 may be insufficient and uneven.

[0007] Therefore, depending on the position in the stacking direction of the setters 4 where the ceramic electronic component green bodies are placed or the position of the ceramic electronic component green bodies in each setter 4, the ceramic electronic component green bodies are not used. The degree of binder removal or sintering becomes non-uniform, and the characteristics of the ceramic electronic component as a finished product may vary.

Accordingly, an object of the present invention is to provide a method for firing a ceramic electronic component unsintered body, which can improve the uniformity of supply of the atmospheric gas to the ceramic electronic component unsintered body as an object to be fired. An object of the present invention is to provide a continuous firing furnace and a method of manufacturing a ceramic electronic component using the same.

[0009]

SUMMARY OF THE INVENTION According to the present invention, a conveying path for conveying a green ceramic electronic component to be fired is formed in a furnace, and the green ceramic electronic component is fired in an atmosphere. Therefore, the present invention is directed to a continuous firing furnace for firing an unsintered ceramic electronic component, which is provided with a gas inlet for introducing an atmospheric gas into the furnace. In order to solve the above problem, a baffle plate for directing the atmosphere gas to the ceramic electronic component green body to be fired is provided.

[0010] The continuous firing furnace according to the present invention preferably has a side wall extending along the transport path, and the gas inlet is located on this side wall.

In the above case, the baffle plate is disposed so as to sandwich the ceramic electronic component green body from the upstream side and the downstream side in the transport direction of the ceramic electronic component green body in the transport path, and the ceramic electronic component green body. It may include one provided so as to move with the green body, or one fixedly provided in the vicinity of the gas inlet.

[0012] The baffle may include a slit provided to allow a part of the atmospheric gas to pass therethrough and thereby to make the atmosphere in the furnace more uniform.

According to the present invention, a plurality of setters stacked in multiple stages are arranged on a transport path so as to form a space between each other, and on each setter, a ceramic electronic component to be fired is unfired. It is particularly advantageously applied to a continuous firing furnace in which the compact is placed.

The present invention is also directed to a method of manufacturing a ceramic electronic component, comprising a step of preparing a ceramic electronic component green body and a step of firing the ceramic electronic component green body. The step of firing the ceramic electronic component green body is performed using such a continuous firing furnace.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In practicing the present invention,
By firing, an unsintered ceramic electronic component that is to be the target ceramic electronic component is prepared. In order to fire this ceramic electronic component green body, a continuous firing furnace as described below is used.

FIG. 1 shows a continuous firing furnace 11 according to a first embodiment of the present invention, and FIGS. 1 (1) and (2).
Respectively correspond to FIGS. 6A and 6B described above.

The continuous firing furnace 11 has a transfer path 12 through which a ceramic electronic component green body (not shown) to be fired is transferred, and is formed along the transfer path 12. The plurality of transport base plates 13 are arranged in a continuous state. During the firing, the transport base plate 13 moves the transport path 12
Is moved along.

A plurality of multi-stage setters 1 made of, for example, alumina are provided on each of the transport base plates 13.
4 are arranged. Each setter 14 is installed so as to form a space 15 between each other when stacked in multiple stages. The unsintered ceramic electronic component as an object to be fired is placed on each setter 14.

Further, the continuous firing furnace 11 is provided with a gas inlet 16 for introducing an atmospheric gas into the furnace. The plurality of gas inlets 16 are located on the side wall 17 of the continuous firing furnace 11 so as to face each other across the setter 14 and to be distributed along the transport path 12.

The above configuration is substantially the same as that of the conventional continuous firing furnace 1 shown in FIG.

As a characteristic configuration in this embodiment,
The setter 14, that is, the ceramic electronic component green body is sandwiched from the upstream and downstream sides in the transport direction of the ceramic electronic component green body in the transport path 12.
8 are arranged. The baffle plate 18 is mounted on the carrier base plate 13 and is thereby provided so as to move with the setter 14, that is, the ceramic electronic component green body.

The baffle plate 18, as indicated by an arrow 19, sends the atmospheric gas ejected from the gas inlet 16 to the setter 1.
4 so as to be directed to the unsintered ceramic electronic component as an object to be fired placed on 4.

As described above, by providing the baffle plate 18, the atmospheric gas introduced from the gas inlet 16 diffuses into the other furnace space before being supplied to the space 15 between the setters 14. Therefore, the ambient gas can be forcibly fed toward the ceramic electronic component green body as the object to be fired, which is located in the space 15 between the setters 14, and as a result, during firing, In this case, the atmospheric gas can sufficiently and uniformly act on the green body of the ceramic electronic component. This is particularly effective in the case where the setter 14 intermittently and continuously moves on the transport path 12 and faces the gas inlet 16 when the setter 14 stops.

FIG. 2 is a side view of a baffle plate 18a for explaining a second embodiment of the present invention.

A plurality of slits 20 are provided on the baffle plate 18a shown in FIG. These slits 20
It is provided as necessary and allows a part of the atmospheric gas to pass therethrough, thereby acting to make the atmosphere in the furnace more uniform.

The baffle plate 18a provided with the slits 20 is provided in place of the baffle plate 18 in the continuous firing furnace 11 shown in FIG. Or
A part of the baffle plate 18 may be replaced while considering the most effective arrangement and number for uniformizing the atmosphere in the furnace.

FIG. 3 shows a continuous firing furnace 11a according to a third embodiment of the present invention. FIGS. 3 (1) and (2) show the above-described FIGS. 1 (1) and (2), respectively.
It corresponds to. In FIG. 3, elements corresponding to the elements shown in FIG. 1 are denoted by the same reference numerals, and redundant description will be omitted.

In the continuous firing furnace 11a shown in FIG. 3, the setter 1 is used as a baffle plate from the upstream side and the downstream side in the transport direction of the ceramic electronic component green body in the transport path 12.
4, which is arranged so as to sandwich the ceramic electronic component green body and is mounted on the carrier base plate 13, whereby the setter 14, that is, a baffle plate 18 provided to move together with the ceramic electronic component green body In addition, a baffle plate 21 fixedly provided near the gas inlet 16 is provided.

The latter baffle plate 21 is indicated by an arrow 2 shown by a solid line.
As shown by 2, the atmosphere gas blown from the gas inlet 16 acts so as to be directed to the ceramic electronic component green body as the object to be fired placed on the setter 14.

The size and position of the baffle plate 21 are selected so as not to hinder the movement of the baffle plate 18.

In this embodiment, the baffle plate 21 is
As indicated by the dashed arrow 23, a slit 24 is formed that allows the passage of a portion of the ambient gas, thereby acting to make the atmosphere in the furnace more uniform.

In FIG. 3A, the atmosphere gas flowing through the slit 24 strikes the baffle plate 18 and changes its direction, as shown by the arrow 23. In addition, the atmospheric gas that strikes 18 is not limited to this, and the atmospheric gas blown out from the gas inlet 16 directly passes through the baffle plate 1 without passing through the slit 24.
It may hit 8.

As described above, by providing not only the baffle plate 18 but also the baffle plate 21, it becomes easier to control the direction of the atmosphere gas introduced from the gas inlet 16 and, therefore, during firing. In addition, the atmosphere gas can more sufficiently and uniformly act on the green body of the ceramic electronic component. Further, in the case of this embodiment, the above-described effect is more remarkably exhibited in the case where the setter 14 intermittently moves along the transport path 12 and faces the gas inlet 16 when the setter 14 stops. .

According to this embodiment, the baffle plate 21
Is provided with a slit 24, so that a part of the atmospheric gas passes through the slit 24 and diffuses into the furnace.
This can contribute to the uniformization of the atmosphere in the furnace, and can further increase the flow of the atmosphere gas hitting the baffle plate 18.

FIG. 4 shows a continuous firing furnace 11b according to a fourth embodiment of the present invention. FIGS. 4 (1) and (2) show the above-mentioned FIGS. 3 (1) and (2), respectively.
It corresponds to. In FIG. 4, elements corresponding to the elements shown in FIG. 3 are denoted by the same reference numerals, and redundant description will be omitted.

The continuous sintering furnace 11b shown in FIG. 4 is characterized in that only a baffle plate 21 fixedly provided near the gas inlet 16 is provided as a baffle plate.

Also in this embodiment, by providing the baffle plate 21, the ambient gas introduced from the gas inlet 16 diffuses into the other furnace space before being supplied to the space 15 between the setters 14. This is suppressed as indicated by the arrow 22, so that the atmospheric gas is forcibly fed toward the ceramic electronic component green body as the object to be fired located in the space 15 between the setters 14. As a result, the atmosphere gas can sufficiently and uniformly act on the ceramic electronic component green body during firing.

Also in this embodiment, the baffle plate 2
1 is provided with a slit 24, a part of the atmosphere gas passes through the slit 24 and diffuses into the furnace as shown by an arrow 23, and therefore, it is possible to contribute to uniformity of the furnace atmosphere. it can.

FIGS. 5A and 5B are views for explaining a fifth embodiment of the present invention. FIG. 5A is a plan view showing a baffle plate 25 together with a gas introduction port 26, and FIG. 25
FIG.

The baffle plate 25 shown in FIG. 5 has a shape having a bent portion 27 and is attached so as to extend from the gas inlet 26. Further, the baffle plate 25 is provided with a slit 28 so as to straddle the bent portion 27.

The baffle plate 25 may be, for example, the continuous firing furnace 11a shown in FIG. 3 or the continuous firing furnace 11 shown in FIG.
In b, the baffle plate 21 is provided instead of the baffle plate 21, but may be replaced with all the baffle plates 21 or may be replaced with a part of the baffle plate 21.

The present invention is characterized in that a baffle plate is provided for directing the atmospheric gas from the gas inlet to the unsintered ceramic electronic component as an object to be fired. The shape, size, position, etc. of the continuous firing furnace vary depending on the shape and size of the continuous firing furnace, the transport mode and the loading mode of the ceramic electronic component green body as the object to be fired on the transport path.

An experimental example performed to confirm the effects of the above embodiment will be described.

In order to obtain a multilayer ceramic capacitor having a size of 3.2 mm × 1.6 mm × 1.6 mm, firing is performed by the continuous firing furnace 11 shown in FIG. 1, the continuous firing furnace 11b shown in FIG. Were carried out using the continuous firing furnace 1 shown in Table 2 above, and the capacity variation of the obtained multilayer ceramic capacitor was evaluated. The results are shown in Table 1 below.

[0045]

[Table 1]

In Table 1, Samples 1 to 4 are samples obtained by firing using the conventional continuous firing furnace 1 shown in FIG. 6, and Samples 5 to 8 are diagrams according to the embodiment of the present invention. 4 are samples obtained by firing using the continuous firing furnace 11b shown in FIG. 4, and samples 9 to 12 are obtained by firing using the continuous firing furnace 11 shown in FIG. 1 according to the embodiment of the present invention. Sample.

In Table 1, "setter area" indicates the relative value of the plane dimension of the setter 4 or 14 used, and "2S" indicates that the area is twice as large as "S". ing.

The "introduced gas amount" indicates a relative value of the introduced amount of the atmospheric gas introduced from the gas inlet 6 or 16, and "2L" indicates that it is twice "L". ing.

In this experimental example, the maximum temperature in the continuous firing furnaces 1, 11 and 11b was set to 1240 ° C.
The object to be fired is a continuous firing furnace 1, 11 or 1 for 28 hours.
1b, and N ₂ + H ₂ + H ₂ O was used as an introduced gas.

As can be seen from the "capacitance variation" in Table 1, Sample 1 does not satisfy the target value of the capacitance variation of 3% or less. Even in the case of the sample 3 in which the amount of the introduced gas is twice as large as that of the sample 1, the variation in capacity is hardly improved. From this,
Atmosphere gas introduced from the gas inlet 6 is not sufficiently supplied between the stacked setters 4, and it is understood that the gas replacement efficiency in the vicinity of the unsintered multilayer ceramic capacitor as an object to be fired is poor. . When the setter area is doubled as in Samples 2 and 4, the variation in capacitance is greatly increased.

On the other hand, Samples 5 to 8 and 9 to 1
According to No. 2, regardless of the conditions of the setter area and the amount of introduced gas, all satisfy the target value of the capacity variation of 3% or less. This indicates that the supply of the atmospheric gas to the unsintered multilayer ceramic capacitor as the object to be fired and the gas replacement in the vicinity of the unsintered multilayer ceramic capacitor are sufficiently, efficiently and uniformly performed. I understand.

[0052]

As described above, according to the present invention, in the continuous firing furnace, the atmosphere gas introduced into the furnace from the gas inlet for firing the green body of the ceramic electronic component in the atmosphere is prevented by the baffle plate. Is intended to be directed to the ceramic electronic component green body to be fired, so that the ambient gas diffuses into the other furnace space before being supplied to the ceramic electronic component green body. As a result, the supply of the atmosphere gas to the ceramic electronic component green body is sufficiently performed, and the supply of the atmosphere gas can be made uniform. Therefore, it is possible to make it difficult for the characteristics of the ceramic electronic component obtained by firing to vary.

In the continuous firing furnace according to the present invention, when the gas inlet is located on the side wall extending along the transfer path, the baffle plate is moved in the transfer direction of the ceramic electronic component green body in the transfer path. It is arranged so as to sandwich the ceramic electronic component green body from the upstream side and the downstream side, and is provided so as to move together with the ceramic electronic component green body, or is fixedly provided in the vicinity of the gas inlet. By doing so, it is possible to more reliably achieve the above-described effect of enabling sufficient supply of the atmospheric gas and uniform supply.

Further, the baffle plate is arranged so as to sandwich the ceramic electronic component green body from the upstream side and the downstream side in the transport direction of the ceramic electronic component green body in the above-described transport path. If both are fixedly provided in the vicinity of the gas inlet, it is easier to control the direction of the atmospheric gas introduced from the gas inlet, and therefore, during firing, the ceramic The atmosphere gas can more sufficiently and uniformly act on the electronic component green body.

In the present invention, if the baffle plate is provided with a slit that allows a part of the atmospheric gas to pass,
When a part of the atmosphere gas passes through the slit, the atmosphere in the furnace can be made uniform.

Further, a plurality of setters stacked in multiple stages so as to form a space between each other are arranged on the transfer path of the continuous firing furnace, and the ceramic electronic parts to be fired are placed on each setter. When the union is placed, it becomes difficult to sufficiently supply the atmosphere gas to the space between the setters, so that the effect of the baffle plate, which is a characteristic configuration of the present invention, can be more remarkably exhibited. .

[Brief description of the drawings]

FIG. 1 is a continuous firing furnace 1 according to a first embodiment of the present invention.
1 is a plan view showing a part of the continuous firing furnace 11, and FIG. 2B is a sectional view of the continuous firing furnace 11.

FIG. 2 is a side view showing a baffle plate 18a for explaining a second embodiment of the present invention.

FIG. 3 is a continuous firing furnace 1 according to a third embodiment of the present invention.
1A is a plan view showing a part of a continuous firing furnace 11a, and FIG. 2B is a cross-sectional view of the continuous firing furnace 11a.

FIG. 4 is a continuous firing furnace 1 according to a fourth embodiment of the present invention.
1B is a plan view showing a part of the continuous firing furnace 11b, and FIG. 2B is a sectional view of the continuous firing furnace 11b.

5A and 5B are views for explaining a fifth embodiment of the present invention, wherein FIG. 5A is a plan view showing a baffle plate 25 together with a gas introduction port 26, and FIG. 5B is a side view of the baffle plate 25; FIG.

FIG. 6 shows a conventional continuous firing furnace 1 of interest to the present invention.
(1) is a plan view showing a part of the continuous firing furnace 1, and (2) is a sectional view of the continuous firing furnace 1.

[Explanation of symbols]

 11, 11a, 11b Continuous firing furnace 12 Transport path 14 Setter 15 Space 16, 26 Gas inlet 17 Side wall 18, 18a, 21, 25 Baffle plate 19, 22, 23 Arrow indicating the flow of atmospheric gas 20, 24 Slit

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Toshinori Kawahara 2-26-10, Tenjin, Nagaokakyo-shi, Kyoto Inside Murata Manufacturing Co., Ltd. (72) Toshiki Nishiyama 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Stock Company In Murata Manufacturing (72) Inventor Yasunobu Yoneda 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto F-term in Murata Manufacturing Co., Ltd. 4K050 AA04 BA16 CC08 4K063 AA06 AA15 BA04

Claims (7)

[Claims] A transfer path through which a ceramic electronic component green body to be fired is transferred is formed in a furnace, and an atmosphere is provided in the furnace to fire the ceramic electronic component green body in an atmosphere. A continuous firing furnace for firing a ceramic electronic component green body provided with a gas inlet for introducing a gas, wherein the atmosphere gas is converted into a ceramic electronic component green body to be fired. A continuous firing furnace, wherein a baffle for directing is provided. 2. The continuous firing furnace according to claim 1, further comprising a side wall extending along the transport path, wherein the gas inlet is located on the side wall. 3. The ceramic electronic component, wherein the baffle plate is disposed so as to sandwich the ceramic electronic component green body from an upstream side and a downstream side in a transport direction of the ceramic electronic component green body in the transport path. 3. The continuous firing furnace according to claim 2, including one provided to move with the green body. 4. The continuous firing furnace according to claim 2, wherein the baffle plate includes one fixedly provided near the gas inlet. 5. The baffle, including those provided with slits that allow a portion of the ambient gas to pass through, thereby providing a more uniform atmosphere in the furnace. Item 5. A continuous firing furnace according to any one of Items 1 to 4. 6. A plurality of setters, which are stacked in multiple stages so as to form a space between each other, are arranged on the transport path, and a ceramic electronic component to be fired is placed on each setter. 6. The continuous firing furnace according to claim 1, wherein the body is placed. 7. A method for manufacturing a ceramic electronic component, comprising: a step of preparing a ceramic electronic component green body; and a step of firing the ceramic electronic component green body. A method for manufacturing a ceramic electronic component, comprising performing the firing step using the continuous firing furnace according to any one of the above.