JPS5815207A - Method of producing ceramic electronic part - 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 a method of manufacturing a ceramic electronic component in which gold 11J-doped wires are embedded.

All ceramics used in thermistors and various sensors are provided with electrodes, and these electrodes are often formed by coating or baking conductive paint, or by vapor deposition of metal. All of these electrodes cannot be used at temperatures above several hundred degrees due to oxidation and peeling.Ceramic components used at temperatures above the electrode's operating range, such as high-temperature thermistors and gas sensors, are made of ceramic. A platinum wire or a gold wire is embedded in a compacted powder of a material, integrally molded, and fired, and the metal lead wire and ceramic base are fixed to form an il. In this method, the compact shrinks by 10 to 30 inches during firing, but the metal wire does not, so compressive force is applied to the metal wire,
It is possible to firmly bond the ceramic substrate and the metal wire. However, if the ceramic substrate cannot withstand the stress generated by the above-mentioned shrinkage, the ceramic substrate will break. The degree of shrinkage due to firing and the mechanical strength of the substrate depend on the chemical composition of the materials that make up the ceramic and the composite force method. On the other hand, what is required for ceramic electronic components is electrical 8+! However, no matter how good the electrical characteristics are, if it is fixed to the lead wire,
If the ceramic substrate is destroyed, it cannot be used as an electronic component, so as long as manufacturing methods such as "Double Series" were used, the usable chemical group was limited to 1 k. Furthermore, if the metal wire to be embedded is thin, the stress applied to the ceramic base is small and destruction is less likely to occur, but if a thick wire is used to increase the strength of the metal wire, the ceramic base will be destroyed.

Since such destruction occurs due to the stress caused by the difference in shrinkage between the powder compact and the metal wire as described above, it is sufficient to prevent this stress from exceeding the crushing strength of the ceramic substrate. For this reason, the diameter of the metal wire should be 1
There is also a method in which a hole with a diameter 0 to 30% larger is made, a metal wire is inserted into the hole, and then fired. In this case, holes must be formed in the brittle green compact, and the green compact may collapse or chip during processing.

The method of the present invention solves the above-mentioned problems, and after providing an organic coating layer on the surface of the platinum wire or gold wire,
Ceramic electronic components are obtained by integrally molding powder with the required chemical composition and firing. Before firing, an organic coating layer exists between the metal wire and the powder compact, but during the firing process, this organic coating layer decomposes and burns at 200 to 500°C, causing the gap between the powder compact and the metal wire to decompose and burn. A gap is created between the two, and the temperature force ≦
Contraction of the green compact occurs after it rises. Therefore, if the thickness of the organic coating layer is set in advance in accordance with the shrinkage rate of the green compact, destruction of the ceramic substrate can be prevented.

Next, embodiments of the present invention will be explained using drawings. First, Mq (A1.5
A powder of Cras Fe, ), o4 was prepared and mixed with 6% by weight of polyvinyl alcohol/L aqueous solution having a concentration of 6% as a binder. next,
“The platinum wire 1 was immersed in an aqueous solution of polyvinyl alcohol, pulled up and dried. On the surface of the dried platinum wire 1, a coating layer 2 of polyvinyl alcohol was formed as shown in FIG. 1. The platinum wire 1 subjected to this process was integrally molded with the powder into the shape shown in Fig. 2 using a conventional method.In the figure, (3 is a green compact). For comparison, a test was also carried out using a platinum wire not coated with polyvinyl anhydride (1-6).The table below shows the failure rate of the stiff fired 7-ramic substrate.

As is clear from the table, the organic coating layer is effective in preventing destruction of the ceramic substrate, and the effect is particularly significant when the thickness is 10% or more of the metal wire diameter.

As described above, according to the method of the present invention, an organic coating layer is provided on at least the red part of the metal wire to be embedded in the ceramic base, and is integrally molded with the ceramic IGt 1 and fired. During firing, the organic coating layer of ζ is burned away, and the stress generated in the ceramic substrate due to the difference in coefficient of thermal expansion from the metal wire to that of the metal wire can be effectively reduced due to contraction of the green compact. If the thickness of the organic coating layer is determined according to the degree of shrinkage of the green compact, it is possible to fabricate a green compact with metal wires embedded in it using a known method. Easy to use.

[Brief explanation of the drawing]

The drawings are for explaining the present invention in detail. Figure 1 is a cross-sectional view of a metal wire coated with an organic coating layer, and Figure 2 is a perspective view of a green compact in which the metal wire is embedded. be. 1... Platinum wire, 2... Polyvinyl alcohol coating layer, 3... Green compact. Name of agent: Patent attorney Toshio Nakao and 1 other person
1 Figure 71 1 1, /

Claims (1)

[Claims] In a method for manufacturing a ceramic electronic component in which a metal wire is embedded in a ceramic base, an organic coating layer is provided on the surface of at least a portion of the metal wire to be embedded in the ceramic base, and after integrally molding with ceramic raw material powder, firing is performed. A method for manufacturing a ceramic electronic component, characterized by: