JPS634338B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for manufacturing ceramic electronic components, and an object of the present invention is to provide ceramic electronic components that are easy to manufacture, inexpensive, and have stable characteristics. Conventionally, electrodes of ceramic electronic components that utilize the functional characteristics of dielectric elements, piezoelectric elements, etc. have been coated with metals, mainly noble metals such as Ag, Ag-Pd, Ag-Pt, and Ag-Ni, on the surface of the ceramic material. A baked mixture is used, but various plating methods are being developed in response to the recent rise in the price of precious metals. However, these methods have many drawbacks; for example, it is possible to form baked silver electrodes on the surface of the porcelain body and then provide metal electrodes by electrolytically plating nickel electrodes and silver electrodes; In this method, the surface of the baked metal layer is rough and has many small pores, so the plating liquid penetrates into the small holes during the plating process, which reduces the adhesion strength between the baked metal layer and the porcelain body. Ta. Another method used is electroless plating, and in the case of nickel plating, it is common to first perform a catalyst activation treatment by a chemical reaction between stannous chloride and palladium chloride. However, there are many problems when using this method as a method for forming electrodes for ceramic electronic components such as dielectric elements, piezoelectric elements, and semiconductor elements. In other words, the tensile strength, capacitance, loss angle, dielectric constant, etc. may decrease depending on the type of electrode material and related materials and the mounting method, and the change rate of capacitance temperature characteristics, moisture resistance load life characteristics, etc. may vary as piezoelectric elements or capacitors. This is due to the deterioration of the characteristics of the For example, in the case of the electroless nickel plating method, due to the nature of the method, a metal film is likely to be formed on the entire circumferential surface of the substrate, so the film on the circumferential side surface must be ground away to form a counter capacitor electrode. In this case, since the creepage withstand voltage distance is determined by the thickness of the substrate, dielectric breakdown is likely to occur due to a short circuit at the peripheral edge of the electrode, and the thickness of the substrate cannot be made very thin. In contrast to these methods, a partial plating method involves applying a plating resist to the required locations on the porcelain surface in advance when forming a metal layer with a desired pattern on the porcelain surface, and then removing the plating resist after activating the porcelain. However, various methods are known, such as applying electroless plating to form a metal layer on the porcelain surface, vacuum evaporation method, and photo-etching method. As an electrode, satisfactory results could not be obtained.
That is, these conventionally known plating methods have poor plating adhesion and poor mass productivity. Taking a capacitor as an example, a small, large capacity capacitor has an element thickness of 0.1 mm to 0.3 mm.
It is as thin as 1.0 mm and comes in various shapes ranging from 4.5 mm to 16 mm, making it difficult to mass-produce it. Furthermore, when electrodes are formed on the entire surface in order to increase the capacitance value even slightly, the life characteristics become extremely poor as described above, and there are many problems in terms of reliability. The present invention eliminates many of the above-mentioned drawbacks and provides a method for manufacturing ceramic electronic components having extremely stable properties. That is, in the manufacturing method of the present invention, a solution containing a metal component composed of at least one of a metal compound and a fine metal powder is applied to a ceramic substrate and dried, and a resist is applied to the required areas of this substrate and dried and hardened. After removing metal components other than the resist area, the substrate is heat-treated at a temperature range of 350 to 900°C to deposit metal fine particles at the required locations on the substrate, and then electroless plating is performed to deposit nickel, cobalt, copper, and gold. It forms a metal electrode,
The ceramic electronic component obtained by the method of the present invention has very good characteristics and can provide sufficient functionality. Examples of the present invention will be described in more detail below. As a ceramic that utilizes functional characteristics,
A substrate made of ceramic material such as BaTiO ₃ -BaZrO ₃ , TiO ₂ , or SrTiO ₃ with a thickness of 0.3 mm and a shape of 12 mm is used, and a solution containing nitrates such as nickel, cobalt, and iron is applied to the surface of this substrate. After drying, nitrates of Ni, Co, and Fe were deposited on the substrate surface. Etching resist was applied by spraying or printing using a mask that left a 1 mm edge on both sides of the substrate, and was dried and hardened. Next, metal components other than the resist area are removed by etching using acid and water, and then the resist is burnt off by heat treatment in the temperature range of 350 to 900°C, and nickel is added to the necessary areas.
Fine particles of metals such as cobalt and iron were precipitated. This substrate was then treated with nickel in a solution containing Pd ions.
After performing a substitution treatment to replace the surface of metal fine particles such as cobalt and iron with Pd, they were immersed in an electroless plating solution containing nickel sulfate and sodium hypophosphite to form a nickel film. Next, as a lead terminal attachment,
Lead wires were attached using a dipping method using a Pb-Sn based solder material, and then coated with a phenol resin and impregnated with wax to create a finished product. Table 1 shows the characteristics of dielectric capacitors manufactured by the above method. Note that in Table 1, hydrochloric acid is used as the dilute acid.

【table】

[Table] In Table 1, No. 1 to No. 6 are results in which the resist baking temperature is changed while keeping the metal component constant, and No. 7 to No. 9 are results in which the resist baking temperature is kept constant and the metal component is changed. It is a different type. As is clear from the table, resists whose baking temperatures are within the range of the present invention have good dielectric properties. In addition, No. 7 to No. 9 are cases in which the type of metal component was changed, but each showed good results. In the above example, the metal components are Ni, Co,
Fe nitrate was used, but the metal components were Pd,
Precious metals such as Pt, Ag, Au, Rh, Ru, Ir, Os,
Ni, Co, Fe, Cu, Zn, Cd, Mg, In, Sn, Pb,
It may be made of at least one of a metal compound of a base metal such as Bi, Cr, and Mn, and a fine metal powder. Furthermore, although a solution containing a metal component is used in the present invention, any method may be used as long as the metal fine particles remain on the substrate surface after baking. In addition, in the above examples, before electroless plating, the metal particles were immersed in a solution containing Pd ions to perform a substitution treatment, but this gives a catalytic effect to the metal fine particles deposited by baking, and also strengthens the catalytic effect. In particular, Zn, Cd,
It is always required for base metals such as Mg, In, Sn, Pb, Bi, Cr, and Mn. In addition, in the present invention, the reason why heat treatment is performed in the temperature range of 350 to 900°C is to precipitate fine metal particles on the substrate surface with good adhesion and burn off the resist organic film. remains, resulting in a decrease in tensile strength after plating, and further deterioration of various properties such as piezoelectric properties, resistance properties, dielectric properties, and varistor properties. At temperatures above 900°C, piezoelectric properties, resistance properties, dielectric properties, varistor properties deteriorate, and life characteristics deteriorate. Furthermore, if a solution containing a metal component is applied to a ceramic substrate, dried, and then heat treated at a temperature of 200 to 900°C to precipitate and bake metal fine particles onto the ceramic substrate, the pattern accuracy and adhesion strength will be even better. Furthermore, although the present invention has been described in the case where it is applied to ceramic electronic components that take advantage of its functional characteristics, it is also effective to use it in a method for forming conductor circuits on insulating substrates that can withstand temperatures of 350°C or higher, including ceramics. . As is clear from the above detailed description, the present invention provides a method for forming electrodes on ceramic electronic components by electroless plating, using a solution containing a metal component consisting of at least one of a metal compound and a fine metal powder. is applied to a ceramic substrate and dried, and after removing metal components other than the necessary parts using a resist, the substrate is heat-treated at a temperature range of 350 to 900°C to deposit metal fine particles at the necessary parts of the board, and then electroless This method forms metal electrodes by plating, and has many industrial values, such as having properties comparable to those of conventional methods, having great cost advantages, and being compatible with industrial mass production. It is something that you have.

Claims (1)

[Scope of Claims] 1. A solution containing a metal component composed of at least one of a metal compound and a metal fine powder is applied to a ceramic substrate and dried, and a resist is applied to the required portions of this substrate and dried and hardened to form a resist portion. After removing other metal components, the substrate is heat-treated in a temperature range of 350 to 900°C to deposit metal fine particles at necessary locations on the substrate, and then metal electrodes are formed by electroless plating. Method of manufacturing ceramic electronic components. 2. The method of manufacturing a ceramic electronic component according to claim 1, wherein a solution containing a metal component is applied to a ceramic substrate, dried, and then heat-treated at a temperature of 200 to 900°C.