JPH059518B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a plating base treatment method as a pretreatment when plating an electrically insulating inorganic material such as glass or ceramic. More specifically, the present invention involves forming an electrically conductive base film on the surface of an electrically insulating inorganic material such as ceramic, which cannot be electroplated, and depositing an electrically conductive layer of metal such as copper or nickel on the base film. This is a surface treatment method for making plating possible, and the uses of the final product of electrically insulating inorganic material treated by the plating surface treatment method of the present invention are as follows:
In the electronics and electrical field, circuits are plated on insulating ceramic substrates, and in the heating field, the surface of ceramic substrates with low thermal conductivity is plated with metals with high thermal conductivity, such as copper, gold, and silver, to ensure uniform temperature distribution on the substrate. These are hot plates and far-infrared heater boards. (Prior art) Conventionally, in this type of plating surface treatment method, in order to impart conductivity to the surface of an electrically insulating inorganic material, a paste prepared by kneading conductive metal powder with an organic binder is applied to the surface of the electrically insulating inorganic material using a brush. A method of coating the surface by painting, roller coating, screen printing, etc. and then sintering it, or a method of physically adhering it by spraying metal powder on the surface at high speed, or a method of spraying a metal chloride solution on the surface, A method of forming a thin metal film on the surface is known. (Problems to be Solved by the Invention) The conventional plating surface treatment method described above has the disadvantage that in the case of a sintering method, it is difficult to coat uniformly and the workability is poor due to the paste or viscosity. In the case of the method of physically adhering the metal powder, it is necessary to use special equipment to spray the metal powder, and there are disadvantages such as the weak adhesion strength of the metal powder to the inorganic material. In the case of the method of forming a thin film by spraying a chloride solution, since metal chloride is used, it is inevitable that chlorine or chloride will be mixed into the metal thin film formed on the surface. As a result, the metal plating material, such as copper or nickel, which is subsequently applied to the surface of the inorganic material, is not only corroded and discolored by the chlorine or chloride present in the underlying metal thin film, but also deteriorates in quality. There are disadvantages in that the conductivity of the plating material decreases and rust occurs. (Means for Solving the Problems) An object of the present invention is to provide a method for plating the base of electrically insulating inorganic materials that eliminates the above-mentioned disadvantages. The surface of the insulating inorganic material to be plated is heated to 400°C to 700°C, and an alcoholic solution of dibutyltin diacetate or dibutyltin diacetoacetonate and ethoxyantimony is applied to the surface to form a conductive ceramic thin film as the final product. The method is characterized in that a conductive ceramic thin film is formed on the surface by spraying. In the present invention, the conductive ceramic thin film is a tin oxide-antimony oxide thin film in which tin oxide is doped with a small amount of antimony oxide. Then, organic compounds of tin such as dibutyltin diacetate and dibutyltin diacetoacetonate and organic compounds of antimony such as ethoxyantimony are used as raw materials for the conductive ceramic thin film, and a small amount of the latter is added to the former and ethanol is added. It was made into a solution dissolved in an alcohol such as . The reason why the surface to be plated is heated to 400℃ to 700℃ is because thermal decomposition of the raw material is difficult to occur below 400℃, and if it exceeds 700℃, the raw material will be thermally decomposed before reaching the surface. This is because the thin film is not sufficiently formed. Therefore, 500℃~600
Particularly preferred is heating at .degree. (Example) Next, an example of the present invention will be described. First, a sintered cordierite substrate having the molecular formula 2MgO ₂ .2Al ₂ O ₃ .5SiO ₂ is heated to 500° C. in an electric furnace. At this time, all the lipids on the substrate were delipidated. Next, each of sample solutions No. 1 to No. 2 containing raw materials for conductive ceramics consisting of the components shown in the table below were sprayed at a spray pressure of 0.8 Kg/cm ² to 1.2 Kg/cm ² at 500 kg/cm 2 .
A ceramic thin film was formed by spraying onto a substrate whose temperature was adjusted to ℃. All of the ceramic thin films obtained with sample solutions No. 1 and No. 2 were uniform thin films with a thickness of about several thousand angstroms that adhered firmly to the substrate.

[Table] Next, each substrate treated with the above sample solutions No. 1 to No. 2 was immersed in an electroless nickel bath with a nickel concentration of 5.0 g/l and heated to 90 to 100°C. , each board was well plated. Although electroless plating was performed in this example, it goes without saying that even better plating can be achieved by electrolytic plating. (Effects of the Invention) As described above, according to the method for plating the electrically insulating inorganic material of the present invention, the surface to be plated is heated to 400°C to 700°C, and a conductive material is formed on the surface as the final product. Since we sprayed an alcoholic solution of dibutyltin diacetate or dibutyltin diacetoacetonate and ethoxyantimony to form a conductive ceramic thin film on the surface, there was no chlorine or chloride in the solution that served as the plating base. Because it does not contain any
Since chlorine does not exist in the conductive ceramic thin film formed on the surface of the electrically insulating inorganic material, the electrically insulating inorganic material is used as a plating base that does not have any effect on the plating material that is subsequently applied to the surface. It has the effect that it is extremely easy to perform a good plating base treatment that adheres firmly to the material with a uniform film thickness.

Claims (1)

[Claims] 1. The surface of an electrically insulating inorganic material such as glass or ceramic to be plated is heated to 400°C to 700°C, and dibutyltin diacetate or dibutyltin diacetoacetonate is applied to the surface to form a conductive ceramic thin film as the final product. 1. A method for plating an electrically insulating inorganic material, which comprises spraying an alcoholic solution of antimony and ethoxyantimony to form a conductive ceramic thin film on the surface.