JP2775936B2 - Manufacturing method of ceramic electronic components - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a ceramic electronic component such as a multilayer ceramic capacitor, and more particularly to an improvement in mechanical strength and electrical characteristics of a thin film ceramic. The purpose is to achieve it.

2. Description of the Related Art To explain a multilayer ceramic capacitor as an example, a general manufacturing method of a multilayer ceramic capacitor is to form a dielectric ceramic powder, an organic binder, and a dielectric film on a carrier film such as polyethylene terephthalate (hereinafter referred to as PET).
And a ceramic slurry comprising an organic solvent is applied by means such as a doctor blade method to form a ceramic green sheet having a predetermined thickness. Thereafter, the internal electrode paste is screen-printed on the ceramic green sheets to be laminated to form an internal electrode layer. The internal electrode paste contains metal particles to be used as internal electrodes, an organic binder, and an organic solvent. The ceramic green sheet on which the internal electrode layers are formed is peeled off from the carrier film, and a plurality of the internal electrodes are stacked and pressed and pressed so that the internal electrodes are alternately led out to different ends to form a laminate, which is cut into a predetermined shape. I do. After cutting, the laminate is fired and the organic binder is burned off at the same time to obtain a fired ceramic body having a plurality of internal electrodes.By forming external electrodes electrically connected to the internal electrodes, a multilayer ceramic capacitor is obtained. Can be

Problems to be Solved by the Invention However, the capacitance of a capacitor is determined by the overlapping area of a pair of opposing electrodes, the distance between the electrodes, and the dielectric constant of the dielectric layer. In order to obtain a small-sized and large-capacity capacitor, it is necessary to reduce the thickness of the dielectric layer. In recent years, there has been an increasing demand for thinner ceramic sheets. However,
The conventional technology has the following problems. That is, the thickness of the ceramic green sheet has conventionally been limited to about 30 μm. However, if the thickness is further reduced, (1) when forming the internal electrode layer on the ceramic green sheet, the organic solvent contained in the internal electrode paste is The ceramic green sheet is eroded. In particular, when the ceramic green sheet is thinned to a thickness of 10 μm or less, the internal electrodes are diffused into the green sheet due to the erosion of the organic solvent, thereby lowering the insulation resistance and lowering the reliability.

(2) Due to the decrease in mechanical strength accompanying the thinning of the ceramic green sheet, peeling failure is caused and mass productivity is impaired.

And other issues.

Accordingly, the present invention provides a method for manufacturing a ceramic laminate which is excellent in handling of thinned ceramic green sheets and improves reliability.

Means for Solving the Problems In order to solve the problems, the production method of the present invention forms a binder film on a carrier film, and forms a ceramic green sheet of a predetermined thickness on the film, and thereafter,
A laminate having a plurality of layers is formed by heat-pressing a three-layered sheet having an internal electrode formed on a surface of a binder film formed by peeling a sheet composed of two layers of an organic binder and a ceramic green sheet from a carrier film. Is obtained.

According to the present invention, since the internal electricity is formed on the binder film coated on the ceramic green sheet, the erosion of the ceramic green sheet by the organic solvent contained in the internal electrode paste is reduced. That is, the organic solvent in the internal electrode is absorbed in the binder layer, the penetration of the organic solvent into the ceramic green sheet is suppressed as much as possible, and the erosion of the ceramic green sheet can be prevented. Further, since the ceramic green sheet is coated with the binder film, the mechanical strength accompanying the thinning of the ceramic green sheet can be compensated for, and the peeling failure from the carrier film can be reduced.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to the drawings, taking a multilayer ceramic capacitor as an example. First, as shown in FIG. 2, a 4 μm-thick
Is formed using a slurry of butyral resin and methyl ethyl ketone. A ceramic green sheet obtained by applying a dielectric ceramic powder containing barium titanate as a main component, the same butyral resin as an organic binder, and a ceramic slurry kneaded using methyl ethyl ketone as an organic solvent to a thickness of 10 μm by a casting method. Form 3 Next, the internal electrodes 4 are formed on the organic binder film 2 of the two-layered sheet peeled from the carrier film 1. A palladium paste is used as an internal electrode material, and an internal electrode having a dry thickness of 1.5 μm is obtained by screen printing to obtain a sheet 5 having a three-layer structure as shown in FIG. A plurality of the sheets 5 having the three-layer structure obtained in this manner are stacked and heated and pressed so that the internal electrodes are alternately led out to different ends, thereby forming a laminate shown in FIG. 60 sheets of the three-layer structure sheet 5 and 10 sheets of the ceramic sheet covered with the organic binder on which the internal electrode is not printed on the upper and lower sides are stacked at 40 ° C. to 80 ° C.
C., at 0.4 to 0.8 ton / cm ² under heat and pressure to be integrated, and then cut along the cutting direction 6 shown in FIG. 3 to obtain a capacitor element 7 independent of the laminate (FIG. 4). . Then, each independent green chip at 200 ° C ~ 4
The organic binders are burned / dissipated at 50 ° C. for 20 hours, and then fired at 1350 ° C. for 2 hours to obtain a device. A silver paste is applied to the end of the element where the internal electrodes are exposed,
By baking at 850 ° C. to form external electrodes, a multilayer ceramic capacitor can be obtained.

Here, in the three-layer structure sheet 5 on which the internal electrodes are formed, the organic binder layer 2 is eroded and deformed by the organic solvent of the internal electrode paste, but burns and disappears during the subsequent heat compression bonding and firing. Thus, it is possible to suppress the penetration of the organic solvent into the ceramic green sheet 3, prevent the electrode from diffusing into the ceramic green sheet, and improve the insulation resistance value. In addition, since the organic binder is coated on the ceramic green sheet, it contributes to improvement in mass productivity in a peeling step and the like.

In this embodiment, the same butyral resin is used as the resin for the organic binder layer and the ceramic green sheet. However, the effect of the present invention is not limited to the combination of these binders. That is, even if a different kind of binder is used for the organic binder layer and the band binder of the ceramic green sheet, or a water-based binder acrylic resin is used for one, water is used for the solvent, and an organic solvent-based binder is used for the other, the effect of the invention is not changed. There is no. Also, when the same type of binder is used for both, when the organic binder layer side has a high degree of polymerization and the ceramic green sheet side has a low degree of polymerization, the erosion degree on the organic binder layer side is reduced and the invention is described. The effect is greater. By the way, in the present embodiment, the thickness of the organic binder layer is set to 2 to 5 μm.
If it is less than 1, the uniformity of the binder layer thickness is hardly obtained, and the effect of improving the mechanical strength of the sheet is not so large. Conversely, if the thickness exceeds 5 μm, internal layer-like defects (delamination) may occur in the sintered body due to heat generated during combustion of the organic binder. Therefore, the effect of the present invention can be obtained by using an organic binder layer having a thickness of 2 to 5 μm.

Effect of the Invention As described above, according to the method for manufacturing a ceramic electronic component of the present invention, in a laminate using a three-layer structure sheet provided with internal electrodes on an organic binder layer coated on a ceramic green sheet, The handling of the sheet is facilitated, the mass productivity can be improved, the diffusion of the internal electrode material can be prevented, and the reliability such as the insulation resistance can be improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a three-layer structure sheet having an internal electrode formed on an organic binder layer coated on a ceramic green sheet according to the present invention, and FIG. 2 is a diagram showing an organic binder layer formed on a PET carrier film. FIG. 3 is a cross-sectional view showing a state in which a ceramic green sheet is formed thereon,
FIG. 4 is a cross-sectional view showing a state in which a plurality of three-layer sheets are stacked, and FIG. 4 is a cross-sectional view showing an independent stacked body. 1 ... PET carrier film, 2 ... Organic binder layer,
3 ... ceramic green sheet, 4 ... internal electrode layer,
5 ... three-layer structure sheet, 6 ... position line indicating cutting direction,
7: Fired ceramic sintered body.

Claims (1)

(57) [Claims] 1. A binder film is formed on a carrier film, a ceramic green sheet having a predetermined thickness is formed on the film, and an internal electrode is formed on the surface of the binder film formed by peeling off the carrier film. A plurality of sheets of the provided three-layer structure are laminated and heat-pressed so that the internal electrodes are alternately led out to different ends to form a laminate. After cutting into a predetermined shape, the laminate is fired. Simultaneously producing a ceramic sintered body having a plurality of internal electrodes by burning out a binder, and forming external electrodes electrically connected to the internal electrodes on the fired laminate. Method.