JPH06112086A - Layered ceramic part and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a method of manufacturing a layered ceramic part which is free from plating elongation even if outer electrodes provided to a laminated ceramic main body are subjected to a plating treatment. CONSTITUTION:Composition such as glass paste 4 which is turned into a glass layer by heating is applied onto the end faces and their adjacent peripheral faces of a layered ceramic main body 1 and dried up, and then Ag-Pd paste 5 is applied onto the end faces and their adjacent peripheral faces of the body 1 smaller than the applied paste 4 in area and baked at a temperature of 500 to 700 deg.C. Then, a nickel plating and a soldering plating process are carried out as usual.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated ceramic component and a method for manufacturing the same.

[0002]

2. Description of the Related Art In order to manufacture a monolithic ceramic component such as a monolithic ceramic inductor, first, a slurry in which a magnetic raw material powder such as Ni--Zn ferrite is mixed with an organic binder is formed into a long sheet, For example, a ceramic green sheet is cut into a square of 110 mm square to prepare a plurality of rectangular ceramic green sheets.
Prepare a frame-shaped stainless frame with a window of 00 mm square surrounded by a width of 15 mm. When these are ready, the ceramic green sheet is attached to the frame. In the corner of the frame, a through hole punch,
At least two holes for positioning in a printing machine, a punching machine, etc. are provided,
These holes are fitted to the pins provided on the printing machine and punching machine to position them, and through holes are opened, a part of the coil conductor pattern is printed, and the ceramic green sheet is made to a predetermined size from the frame. I have punched out.

A coil conductor pattern of a predetermined shape is printed on each of a plurality of ceramic green sheets having through holes, and the ceramic green sheets are stacked and crimped in a predetermined order, and then the pair of opposed end faces of the coil is formed. Although the terminal is led out, it is cut into a chip size at a position where the coil conductor is not exposed on the other end faces.

Next, the chip element is fired at a temperature of about 700 to 900.degree. A conductive paste for an external electrode is applied to the end surface from which the coil end of the fired chip element is led out and baked at a temperature of about 500 to 700 ° C. to form the external electrode, and nickel is formed by electrolytic plating on the surface of the external electrode. Plating is performed, and then solder plating is performed to improve the solder wettability of the external electrodes.

[0005]

SUMMARY OF THE INVENTION In the above conventional method,
In the process of plating the external electrode, the nickel plating layer extends and deposits on the ceramic surface from the edge of the external electrode formed of the conductive paste, and even if there is no extension of the nickel plating layer in the nickel plating process, it remains as it is. When solder plating is applied on the nickel plating layer, there is a phenomenon that the solder expands in the solder plating process, which shorts the electrodes of small electronic components and lowers the withstand voltage between the electrodes. Accordingly, there is a problem that the productivity is lowered because a step of selecting by visual inspection is performed after the plating treatment.

Therefore, an object of the present invention is to provide a monolithic ceramic component which is free from plating elongation even if it is subjected to a plating treatment, and a method for producing the same.

[0007]

Means for Solving the Problems As a result of research to achieve the above object, the present inventors have found that the surface of a laminated ceramic body is
First, a composition for forming a thin glass layer by heating, for example, a treatment such as coating a lead borosilicate glass paste or sprinkling the same with glass powder, and then by baking an external terminal electrode to form a nickel plating on the electrode. Alternatively, they have found that the elongation of the plating, particularly the latter elongation of the solder plating, does not occur when the solder plating is applied, and the present invention has been accomplished.

Therefore, the present invention firstly has an external terminal electrode formed by applying and baking a conductive paste on a pair of opposing end faces of a monolithic ceramic element body and a peripheral surface of the element body which is continuous with the end surface. A multilayer ceramic component having nickel plating and solder plating applied thereon, wherein the glass layer is formed on at least the end face of the element body and its periphery, and the electrode is formed via the glass layer. A laminated ceramic part characterized in that the edge portion of the laminated glass layer is located closer to the end face side than the edge portion of the glass layer; A laminated ceramic including applying a conductive paste to the pair of end faces and the peripheral edge thereof, baking the paste to form an external terminal electrode, and further performing nickel plating and solder plating on the electrode. In the manufacturing method of a product, an external terminal formed on a laminated ceramic body by applying a composition for forming a glass layer by heating on at least an end surface of the body and the peripheral edge thereof, and then heating the composition. A laminated ceramic component characterized by forming a glass layer under the electrode layer at least on the surface of the element body near the edge portion of the electrode layer so that the edge portion of the electrode layer does not come into direct contact with the ceramic element body. A manufacturing method is provided.

[0009]

According to the present invention, since the glass layer is formed on at least the ceramic surface of the peripheral terminal electrode of the laminated ceramic component, the surface condition of the ceramic body is changed and the extension of the electrolytic plating film is prevented. To do. For example, the glass powder in the glass paste melts during baking to form a glass layer that covers the element body, but does not cover up to the internal conductor lead-out portion of the end surface of the element body, causing poor conduction with the electrodes. There is no such thing. Further, instead of using the glass paste, the glass powder itself may be simply sprinkled on the element body. In this case, since the glass powder and the ceramic element body are simply stirred in the container, the treatment can be performed in a short time.

[0010]

[Embodiment 1] FIG. 1 is a perspective view for explaining a method of attaching an external electrode in a method of manufacturing a laminated ceramic component according to this embodiment. The Ni-Zn ferrite magnetic powder was mixed with a binder containing polyvinyl butyral as a main component, and then formed into a sheet to obtain a predetermined number of ferrite green sheets. Then, Ag powder was pasted on these sheets with ethyl cellulose as a binder. The internal conductor paste is printed and stacked in accordance with a predetermined conductor pattern so that a predetermined coil conductor is formed in the magnetic body, and the laminated ceramic green sheets are thermocompression-bonded to the chip element body. A laminated ceramic body in which the chip body is cut and fired in the atmosphere at a predetermined temperature, and a coil conductor end is led out to the end face of the ceramic body 1 as a lead-out portion 2 as shown in FIG. To prepare.

Separately from this, a glass paste having the following composition is prepared. That is, in wt%, SiO _2. 5 to
_{8%, PbO83~87%, B 2} O 3 8~11%, and lead borosilicate glass material powder obtained by mixing, butyl carbitol 60 through 63%, alpha-terpineol 30-33
%, And a binder composed of 7% to 8% of ethyl cellulose in a proportion of 3 binders to 1 glass raw material powder, which is a lead borosilicate glass paste.

When these are prepared, the glass paste 4 is continuously applied to the end surface of the element body and the peripheral surface of the element body continuing to the same as shown in FIG. 1 (b) and dried at a temperature of 110.degree. After that, a commercially available Ag-Pd paste 5 was applied so that the edge after application was on the inner side (edge surface side) of the edge of the layer applied with the glass paste, and baked at a temperature of 600 ° C. Next, electroplating was performed using a normal nickel plating bath, and further electroplating was performed using a solder plating bath to obtain a laminated ceramic component.

As a result of visually observing the edges of the external electrodes of the obtained parts, no nickel plating or solder plating layer elongation was observed.

[0014]

[Embodiment 2] FIG. 3 is a perspective view of another embodiment relating to attachment of external electrodes according to the present invention. In place of the lead borosilicate glass paste in Example 1, S% by weight was used.
iO ₂ 5-8%, PbO 83-87%, B ₂ O ₃ 8-1
A glass powder obtained by crushing 1% of lead borosilicate glass is prepared.

The monolithic ceramic body 1 [FIG. 3 (a)] having the lead-out portion 2 on the end face prepared in the same manner as in Example 1 was put into the above-mentioned lead borosilicate glass powder and mixed to obtain the surface of the body. The whole surface is sprinkled with glass powder 6 [(b) in FIG. 3], and this is baked at 550 ° C. to form a thin glass layer on the surface of the element [(c) in FIG. 3]. External electrodes made of Ag-Pd paste 5 were continuously formed on the peripheral surface of the element body continuous with it, and baked at 700 ° C. [(d) of FIG. 3]. Then, electroplating was performed in the same manner as in Example 1.
No elongation of the nickel or solder plating layer was observed in the obtained multilayer ceramic component.

[0016]

As described above, according to the present invention,
Even if the external electrodes are solder-plated, the solder does not expand, so there is no short circuit between electrodes or reduction in the withstand voltage between electrodes, which is effective in improving the reliability of multilayer ceramic parts. Since the inspection process can be deleted, it contributes to productivity improvement.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating an external electrode attaching method in a method for manufacturing a laminated ceramic component according to an embodiment of the present invention.

FIG. 2 is a perspective view showing solder elongation in a conventional solder plating process.

FIG. 3 is a perspective view showing another embodiment regarding attachment of external electrodes according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ceramic body 2 Drawing part 3 Solder elongation 4 Glass paste 5 Ag-Pd paste 6 Glass powder

Claims (2)

[Claims] 1. An external terminal electrode formed by applying and baking a conductive paste on a pair of opposing end faces of a monolithic ceramic element body and a peripheral surface of the element body continuing to the end surface,
A laminated ceramic component having nickel plating and solder plating applied on the electrode, wherein a glass layer is formed on at least an end face of the element body surface and a peripheral edge thereof, and
A laminated ceramic component characterized in that the edge portion of the electrode formed via the glass layer is present on the end face side with respect to the edge portion of the glass layer. 2. A laminated ceramic element body is formed, and a conductive paste is applied to and baked on a pair of opposing end surfaces of the element body and its peripheral edge to form an external terminal electrode, and nickel plating and In a method for producing a laminated ceramic component including applying solder plating, a composition for forming a glass layer by being heated is applied to at least an end face of the element body and a peripheral edge thereof, and then heated to obtain a laminated body. A glass layer is formed on the surface of the element body at least near the edge portion under the external terminal electrode layer formed on the ceramic element body to prevent the electrode edge portion from directly contacting the ceramic element body. Method for manufacturing laminated ceramic component.