JPS5821813A - Method of producing multilayer ceramic condenser - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in the method of manufacturing multilayer ceramic capacitors.

Conventional methods for manufacturing multilayer ceramic capacitors can be roughly divided into the following two methods. The first has M'y YIi body powder (dispersed in a binder system to form mud I!j7,
Form this into a sheet, print internal electrodes on this green sheet, and print some of these green sheets; i1! i
It is squared and integrated by heating and pressure to form a multi-layered product, then cut into chips and punched out. The second method is to disperse the dielectric-12 powder in a binder system to form a paste in the same manner as above, and then screen-print the dielectric base and internal electrode base alternately on some kind of substrate. ) This is a printing method in which the capacitor is made into a capacitor by cutting into chips, punching out and firing, and then forming terminals.

In the manufacturing method of such multilayer ceramic capacitors, in both the lamination method and the printing method, green sheets, core conductor paste) and internal electrode pastes (mainly Pd
- If the binder system of Ag) and its additions f and 'c are not matched, R: 5
Open-cut IJLc, (Delamination) or Table 11 cracks occur.Delamination occurs when the binder in the dielectric is a little low and there is little binder in the internal mold, 1 wall, 21, Surface cracking is likely to occur when there is a lot of binder in the dielectric material and there is little binder in the internal electric material base.If both binders are increased, this will not occur, but the problem will be that the capacity will be reduced.The present invention was devised during this period to solve i and q.

Therefore, in the present invention, in the method of manufacturing a multi-half ceramic capacitor using a lamination method or a printing method, the green sheets and the binders of the dielectric paste and the internal electric N24 paste all have the same composition, and The amount of each binder added was equal to that of the green sheet and the dielectric base, and was 50 to 80% of the amount of the green sheet and the dielectric paste. be.

The present invention will be explained in detail below based on Examples ((1).

Actual Example 4-1 First, ceramic powder with an average particle size of 1.2 μm (1250℃
A dielectric paste was prepared by dispersing the following binder system in the following binder system.

Table 1 On the other hand, 50 Ag -50Pd (average particle size i, 5tt
m) The powder is dispersed in the binder system so that the amount of 30.40, 50, 60, 70.80, 90% by weight (of the binder (resin and plasticizer)) is An electric carbon paste was prepared.At this time, the addition of a dispersant was the same as that of the dielectric paste, and the solvent was terpineol, and the amount was changed with the amount of binder added to maintain the same viscosity.Next, dielectric paste was added on the substrate. The body paste is applied to a thickness of 250 μm, and the internal paste is applied on top of this by screen printing from A to 8 μm.
Takumi 1. A dielectric paste is applied to a thickness of 40 μn1 on the dibase. After repeating this operation 21 times, a final coating of 250 μm of Shi'ichitai Base I. After coating by screen printing, all the coatings were dried at 120° C. for 8 to 10 minutes. The substrate thus formed into 20 layers (effective sleep-inducing material J+O) was removed, dried at 120° C. for 1 hour, and then cut into Tezzo sheets and subjected to 1iaF. This chip was punched out at 140° C. for 4 hours → 160° C. for 4 hours → 200° C. for 10 hours, and then fired at 1250° C. for 3 hours (temperature increase rate 200'/hour).

Terminal electrodes were attached to these fired chips to produce a finished product. 6. Characteristics of this chip capacitor! J fixed,
The presence or absence of surface cracks and delamination was investigated and the results are shown in Table 2.

Kanayama below Table 2 However, the mark ○ indicates no, and the mark X indicates presence.

From the table, it can be seen that surface cracks and delamination occur in those with a coefficient of 40 or less, and that capacity is insufficient in those with a coefficient of 90 or more. For those between 50 and 80 inches -
Such inconvenience is not recognized including δ.

Example-2 Using the same binder and dispersant as in Example-1, a slurry was made using methyl ethyl ketone as a solvent, and the slurry was made to a thickness of 5.
A 0 μm green sheet was created. An internal electrode paste was also prepared using the same binder and dispersant as in Example 1, but with a different m agent. The solvent used for this internal electrode paste I was one that had a high evaporation rate and did not attack the green sheet as much as possible.

Then, 21 pieces of the above-mentioned <ry r electrode paste printed on the green sheet and dried were stacked on top of each other, and 5 green sheets each without the internal αz-res paste printed on top and bottom were stacked, and heated at 100°C + 10Qk. After laminating the capacitors in a wide area and cutting them into chips, they were made into chip capacitors in the same manner as in Example 1, and the presence or absence of surface cracks and delamination and characteristics were measured. 1 in 1 between words: Exactly the same as in Example 1.

As mentioned above, the method for producing multilayer ceramic contents of the present invention uses the same binder for the dielectric and the internal space. It adheres well to the electrode base and does not cause peeling.Furthermore, by setting the amount of binder in the internal electrode base to 50 to 80 times that of the dielectric, it was possible to prevent scablamination and surface cracking.

Whether or not the capacitance is increased depends on the firing shrinkage rate of the dielectric and the firing shrinkage rate of the internal electrode base. The above firing shrinkage rate is influenced by the particle size of the ceramic powder used for the dielectric and the particle size of the Pd-Ag powder used for the internal electrode base, but if the average particle size of the ceramic powder is 0.5 to 311 m. , Pd-Ag
When the average particle size of the powder is between 0.5 and 3 .mu.m, the amount of binder at which capacity is lost and the amount of binder at which delamination and surface cracking occur are almost the same. Therefore, it is safe within the scope of the present invention.

patent applicant Fujitsu Limited - ζ Permit application agent 17’F Officer Akira Aoki Patent attorney Kazuyuki Nishidate Patent attorney 1) Yukio Patent attorney Akira Yamaguchi

Claims (1)

[Claims] 1, j, □ Silk 5 In a method for manufacturing a multilayer ceramic capacitor using the method or printing method, a green sheet and:'
jKj 'I! The binders for the A1 body paste and the internal mold 1/51 paste are all of the same composition, and the binder additives for each of the former and The manufacturing method of Teishi Ramic capacitors is that the internal type 11 dibase is 50 to 80 layers of green sheet and dielectric base.