JP3175451B2 - Manufacturing method of ceramic green sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a ceramic green sheet used for producing, for example, a multilayer ceramic electronic component, and more particularly, to a ceramic green sheet having an improved process for winding a ceramic green sheet on a reel. And a method for producing the same.

[0002]

2. Description of the Related Art For example, in manufacturing a multilayer capacitor, first, a ceramic slurry containing a ceramic powder, a binder resin, a solvent and the like is applied to a desired thickness on a support film made of a synthetic resin such as polyethylene terephthalate and dried. Thereby, a ceramic green sheet is formed. Next, the ceramic green sheet formed on the support film is peeled off from the support film and wound around a reel.

A ceramic green sheet prepared in a state of being wound on a reel as described above is pulled out from the reel, a rectangular mother ceramic green sheet having a predetermined size is punched out, and a plurality of mother ceramic green sheets are cut out. Get. Thereafter, a conductive paste is printed on one main surface of the mother ceramic green sheet, and then heated and dried. Next, a plurality of mother ceramic green sheets on which an electrode pattern is formed are laminated, and an appropriate number of mother ceramic green sheets on which an electrode pattern is not formed are laminated one above the other, and the laminate is pressed in the thickness direction to form a laminate. obtain. The obtained multilayer body is cut into individual multilayer capacitor units and then fired to obtain a sintered body. By applying external electrodes to both end faces of the thus obtained sintered body, a multilayer capacitor can be obtained.

[0004]

When a ceramic green sheet wound on a reel is prepared as in the conventional manufacturing method described above, tension is applied to the ceramic green sheet when the ceramic green sheet is peeled from the support film. Join. As a result, the ceramic green sheet is stretched by the tension, and is wound around a reel in the stretched state. Therefore, in the wound state, the stress at the time of stretching is not released, and the state is stabilized in the stretched state.

On the other hand, the ceramic green sheet wound as described above is unwound from a reel, punched out to an appropriate size, printed with an electrode pattern, and then heated and dried. The sheet shrinks. The amount of shrinkage of the ceramic green sheet is not constant due to the magnitude of the stress, heating and drying conditions, and the like. Therefore, there is a problem that the dimensions of the ceramic green sheet tend to vary, and even if the electrode pattern is printed with high accuracy, the electrode position accuracy in the finally obtained mother ceramic green sheet varies.

An object of the present invention is to provide a method for producing a ceramic green sheet which is capable of stably supplying a ceramic green sheet having a small shrinkage upon heating and drying and a small dimensional variation.

[0007]

SUMMARY OF THE INVENTION The present invention comprises a step of forming a ceramic green sheet on a supporting film, and cooling the ceramic green sheet to a temperature of the glass transition temperature of the contained binder resin ± 5 ° C. And a step of winding the ceramic green sheet around a reel while removing the ceramic green sheet from the support film.

[0008]

The elongation of the ceramic green sheet depends on the action of the contained binder resin. Therefore, in the present invention, when the ceramic green sheet is peeled from the support film, the ceramic green sheet is cooled to a temperature of the glass transition point tg ± 5 ° C. of the binder resin,
Ceramic green sheets are hard to stretch. Therefore, even if the wound ceramic green sheet is unwound from the reel and heated and dried in a later step,
Since it is not stretched during winding, shrinkage hardly occurs.

[0009]

According to the method for producing a ceramic green sheet of the present invention, the ceramic green sheet is cooled when the ceramic green sheet is peeled off from the support film. Turned. Therefore, even if the ceramic green sheet is unreeled from the reel and heated and dried in a later step, the ceramic green sheet hardly shrinks.

Therefore, it is possible to provide a ceramic green sheet having excellent dimensional stability. For example, when the ceramic green sheet is used in a method of manufacturing a ceramic multilayer electronic component such as a multilayer capacitor, the dimensional variation of the ceramic green sheet and the electrode position accuracy are reduced. It is possible to stably supply a ceramic laminated electronic component having little variation in the above, and to provide a ceramic electronic component having stable characteristics such as capacitance.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be clarified by describing embodiments with reference to the drawings.

FIG. 1 is a schematic side view for explaining one embodiment of the present invention. In this embodiment, first, the support film 1 made of a synthetic resin film such as polyethylene terephthalate is transported in the direction of the arrow shown in the figure. Next, in the sheet forming section 2, a ceramic green sheet 3 is formed by applying a ceramic slurry on the support film 1 to a predetermined thickness and drying the slurry.

As a method for forming the ceramic green sheet 3, an appropriate method such as a doctor blade method or a method using a roll coater can be adopted. Also,
As for the ceramic slurry to be used, those having an appropriate composition obtained by mixing a solvent with various ceramic powders, organic binders and fillers can be used, and are not particularly limited.

Next, when the ceramic green sheet 3 is peeled off from the support film 1, a cooling device 4 is arranged near the part A to be peeled, and cool air is blown. The temperature of the cold air is selected so that the surface temperature of the ceramic green sheet 3 becomes a temperature of the glass transition point tg ± 5 ° C. of the contained binder resin. The cooling by the cooling device 4 is not limited to the cold air, but may be arbitrarily selected such as contact of a cooling pipe. By blowing the cold air, the ceramic green sheet 3 is cooled and wound around a reel (roller) 5. The reel 5 is rotated clockwise as indicated by an arrow in the drawing, and when the ceramic green sheet 3 is wound by the reel 5, tension is applied to the ceramic green sheet 3 in its length direction. However, in this embodiment, since the ceramic green sheet 3 is cooled by the blowing of the cold air, the ceramic green sheet 3 does not extend much due to the tension at the time of winding.

Therefore, even if the mother ceramic green sheet is punched out of the ceramic green sheet wound on the reel 5 and heated and dried after the application of the electrode paste, the shrinkage of the ceramic green sheet hardly occurs.

Next, specific experimental examples will be described. In ceramic powder, polyvinyl acetate as binder resin,
A ceramic slurry formed by mixing pure water as a solvent was formed into a thickness of about 20 μm to obtain a ceramic green sheet 3. Next, the above ceramic green sheet 3
At the time of peeling, various ceramic green sheets 3 were wound around a reel 5 by changing the temperature of the cold air blown from the cooling device 4 shown in FIG. In addition,
For comparison, the ceramic green sheet 3 was wound around the reel 5 without operating the cooling device 4, that is, in the same manner as in the conventional method.

Next, the reel 5 prepared as described above is used.
The ceramic green sheets wound around were wound out from the reel 5 and punched into a rectangular shape of 80 × 60 mm, and the amount of shrinkage after heating to a temperature of 80 ° C. was measured. Table 1 shows the results. The sheet shrinkage shown in Table 1 indicates the amount of shrinkage of the ceramic green sheet in the length direction of 1 mm.

[0018]

[Table 1]

As is evident from Table 1, by cooling the ceramic green sheet to (the glass transition point of the binder resin) + 5 ° C. or less, the sheet shrinkage can be significantly reduced. On the other hand, when the surface temperature of the ceramic green sheet is lower than the temperature at which the viscoelasticity sharply decreases (the glass transition point of the binder resin) -5 ° C., the amount of shrinkage decreases, but the carrier film 2 decreases.
It became difficult to peel from the surface. Therefore, in the ceramic green sheet and the support film used in the above experimental example,
It can be seen that the cooling temperature range of the cooling device 4 is (glass transition point of the binder resin) ± 5 ° C.

[Brief description of the drawings]

FIG. 1 is a schematic side view for explaining a method for manufacturing a ceramic green sheet of an example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Support film 2 ... Sheet forming part 3 ... Ceramic green sheet 4 ... Cooling device 5 ... Reel

Continuation of front page (72) Inventor Yasunobu Yoneda 2-26-10 Tenjin, Nagaokakyo-shi, Kyoto Murata Manufacturing Co., Ltd. (56) References JP-A-63-242601 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B28B 1/30 101 B28B 1/40

Claims (1)

(57) [Claims] 1. A step of forming a ceramic green sheet on a support film, and peeling the ceramic green sheet from the support film while cooling the ceramic green sheet to a temperature of ± 5 ° C. of a glass transition point of a binder resin contained therein. And a step of winding the ceramic green sheet around a reel.