JPH01186606A - Laminated type ceramic capacitor element - Google Patents

Abstract

PURPOSE:To make needless of plating terminal electrodes of a capacitor and of keeping a desiccant in a bag containing the capacitors by coating the whole surface of an element with a high molecular organic film. CONSTITUTION:The whole surface of a ceramic capacitor element having structure in which a ceramic dielectric layer 4 and an inner electrode 3 are alternately laminated is covered with a high molecular organic film 1. At the time of soldering, polystyrene 1 is fore and contracts, causing no bad influence on soldering performance. The solidified and contracted polystyrene dissolves in an organic solvent in flux-washing, not remaining on the ceramic capacitor element at all. Thereby, there is no need of plating terminal electrodes and of keeping a desiccant in a bag containing the capacitor elements, causing no deterioration of the terminal electrodes during long term storage and having no problem in mounting.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a multilayer ceramic capacitor element, and particularly to a multilayer ceramic capacitor that exhibits little deterioration in the characteristics of terminal electrodes when stored at high temperatures and for long periods of time before mounting. Regarding elements.

[Conventional technology]

When soldering the terminal electrodes of a multilayer ceramic capacitor element during mounting, it is sometimes required that the terminal electrodes be covered with almost 100% new solder.

However, since the terminal electrode is mainly made of silver, the problem is that if it is stored for a long time at high temperatures and high humidity, its surface will deteriorate (formation of compounds and dirt), and performance will deteriorate when soldered. was there.

In response to this, proposals have been made such as plating the terminal electrodes and storing a large number of capacitor elements in a hermetically sealed manner by adding desiccant to them.

[Problems that the invention helps solve]

However, plating the terminal electrodes has the disadvantage that the treatment agent damages the ceramic itself, reducing the reliability of the capacitor.

Furthermore, the method of putting a desiccant in a capacitor element and storing it in a hermetically sealed manner is good until just before the capacitor element is opened, but has the disadvantage that the capacitor element is left unprotected after opening until it is mounted.

The purpose of the present invention is to eliminate the need for plating terminal electrodes and enclosing desiccant, which were conventionally performed, in order to improve the reliability of soldering terminal electrodes, and to solve mounting problems that reduce reliability. It is an object of the present invention to provide a multilayer ceramic capacitor element that is free from defects.

[Means for solving problems]

The multilayer ceramic capacitor element of the present invention is characterized in that the entire surface of the ceramic capacitor element, which has a structure in which ceramic electric layers and internal electrodes are alternately laminated, is coated with an organic polymer film. Ru.

Polystyrene is effective as this polymeric organic film.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a perspective view (also a perspective view) of the embodiment shown in FIG.

1 and 2, 1 is a polystyrene film layer, 2 is a terminal electrode, 3 is an internal electrode, 4 is a dielectric layer,
5 is a ceramic capacitor element.

First, the manufacturing method of this example will be explained.

A paste consisting of borosilicate glass, an inorganic binder, and silver was applied as a terminal electrode of a ceramic capacitor element having a structure in which ceramic dielectric layers and internal electrodes were alternately laminated and fired at 600° C. for 1 hour. The external shape of the element after baking is 8. Oxx X 12 [tm.

The thickness is 4i+s.

Next, prepare a 2Qwt% trichlene solution of polystyrene, submerge the device after baking the terminal electrode in it, leave it for 10 minutes under reduced pressure, return to normal pressure, leave it for another 5 minutes, then take it out and heat it at 60℃. Dry for a minute. It was again placed in a 50 wt % polystyrene trichloride solution at normal pressure for about 1 minute, then taken out and dried at 60° C. for 60 minutes.

The thickness of the polystyrene film layer obtained in the above example is about 2 to 3 μm. No damage occurred under normal handling.

Next, the ceramic capacitor element coated with polystyrene and the ceramic capacitor element not coated with polystyrene were left exposed to outside air at room temperature (on a desk in an office) for 6 months, and then the terminal electrodes changed color. The results are shown in Table 1, proving the effectiveness of the present invention.

Table 1 Note that soldering was performed by preheating at 150° C. for 1 minute. At this time, the polystyrene film was torn and shrunk, and there was no adverse effect on soldering performance. The polystyrene that had solidified and shrunk was dissolved in the organic solvent used during flux cleaning, and did not remain in the ceramic capacitor element at all.

We also mounted it on a board, but there was no effect on the mounting performance.

Next, other embodiments of the present invention will be described.

A paste consisting of borosilicate glass, an inorganic binder, platinum, and silver was applied as a terminal electrode of the ceramic element of the first example, and fired at 600° C. for 1 hour.

In this example, as in the first example, polystyrene was applied and dried to produce a polystyrene-covered ceramic capacitor element. Similarly, when the sample was left exposed to outside air at room temperature for 6 months and tested in the same way as in the first example, the results were shown in Table 2, proving the effectiveness of the present invention. There were also no problems with implementation.

Table 2 [Effects of the Invention] Since the entire surface of the multilayer ceramic capacitor element of the present invention is covered with a polymeric organic film, the terminal electrodes will not deteriorate even if left for a long period of time. ,
It exhibits excellent characteristics with no mounting problems, and has great industrial utility value.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a cross-sectional view of one embodiment of the present invention, and FIG.
FIG. 2 is a perspective view (also a perspective view) of the entire figure. 1...Polystyrene film layer, 2...
...Terminal electrode, 3...Internal electrode, 4...
-Dielectric layer, 5... Ceramic capacitor element. Agent Patent Attorney Uchihara Tunka j Zuzuki 2 Seki

Claims (2)

[Claims] (1) A multilayer ceramic capacitor element having a structure in which ceramic dielectric layers and internal electrodes are alternately laminated, and the entire surface of the ceramic capacitor element is coated with an organic polymer film. (2) The multilayer ceramic capacitor element according to claim (1), wherein the polymeric organic file is made of polystyrene.