JPS6056555B2 - How to apply the coating material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating method for uniformly and appropriately depositing a coating material onto the surface of an object to be coated.

For example, when forming electrodes on the surface of dielectric porcelain, a paste obtained by mixing silver, glass frit, solvent, etc. is attached to the porcelain surface by screen printing, spraying, coating, etc., and then heat-treated. Another method is to immerse the dielectric porcelain in the above-mentioned paste and then pull it up and bake it.Furthermore, a conductive solution such as copper chloride is heated to evaporate the gas while the dielectric porcelain is heated. There is a method of forming a conductive film of tin oxide by condensing evaporated gas on the surface. However, all of the above-mentioned methods have the drawback that the electrical characteristics of the obtained capacitors are unstable because the thickness of the electrode material is not constant.

This invention has been made in view of the above-mentioned conventional drawbacks, and provides a method for uniformly and appropriately depositing a coating material such as a conductive paste on an object to be coated such as dielectric porcelain. This adhered body is mixed with an object to be coated that is not magnetically attracted, and the coating material on the surface of the adhered body is uniformly adhered to the surface of the object to be coated, and the material is adhered to the object to be coated. After spreading the coating material,
A device is characterized in that a magnetically attracted object is attracted by magnetic force and separated from the object to be coated. This invention will be described in detail below with reference to Examples. Example 1 While preparing 50 alumina balls with a diameter of 6TrUft,
Paste 100 y (P
Solid content of bO 50 da) and iron ball 100 with diameter 1.5 wrm
g was mixed to prepare an adhered body in which HD paste was adhered to the surface of an iron ball.

Next, put the alumina sphere and the adhered body together in a pot mill,
The Ho paste was adhered to the surface of the alumina spheres by mixing for about one hour while maintaining the temperature at 20 to 100°C.

Further, the iron balls were attracted by a magnet to separate the alumina balls and the iron balls, and then heat-treated at 50 to 200° C. for about 30 minutes to diffuse the Ho paste onto the surfaces of the alumina balls. The surface of each sample obtained was observed with a reflection microscope and the uniformity of the applied material was visually confirmed, and no unevenness was observed on the applied surface, indicating good results.

Further, when the amount of adhesion was measured and the distribution of the amount of adhesion was investigated, the standard deviation value was O.02y.

In addition, the amount of PbO paste attached to the alumina sphere is O,
The variation was determined using 7y as the average amount of adhesion. As a comparative example, an alumina sphere was prepared in the same manner as in the above-mentioned example, and it was immersed in a paste mixed with PbO and organic varnish, and then pulled out to ensure that the uniformity and amount of coating material on the surface of the alumina sphere were as described above. When similarly measured,
The occurrence of unevenness was observed on the surface, and when the distribution of the adhesion amount was investigated, the standard deviation value was 0.4y.

The average amount of adhesion at this time was 0.8y. According to this example, the PbO paste was uniformly adhered to the surface of the alumina sphere, and the variation in the amount of adhesion was small.

Example 2 Five alumina disks with five diameters and a thickness of 0.2 Tnm were prepared, and paste 1 was prepared by mixing Bj2O3 and organic varnish.
00y (solid content of Bl2O3 50y) and diameter 1.0WL
100y of iron balls are uniformly mixed to coat the surface of the iron balls with Bi2O3.
A adhered body to which the paste was adhered was prepared.

Next, the alumina disk and the adhered body were placed together in a pot mill and mixed for about 1 hour while being maintained at a temperature of 20 to 100 DEG C., so that the Bi2O3 paste was adhered to the surface of the alumina disk.

Furthermore, after adsorbing the iron ball with a magnet and separating the alumina disk and the iron ball, heat treatment is performed at 50 to 200°C for about 30 minutes.
Bi2O3 paste was diffused on the surface of the alumina disk.
Regarding the obtained sample, the uniformity and amount of Bi2O3 paste adhered to the surface of the alumina disk were measured in the same manner as in Example 1. No unevenness was observed on the surface, and the distribution of the amount of adhesion was also examined. However, the standard deviation value was 0.01 Da.

Note that the average amount of Bi2O3 paste adhering to the alumina disk was 0.4y. As a comparative example, like this Example 2, the diameter is 5 in order and the thickness is 0.2TTr! Prepare 50 n alumina disks, then heat Bl2O3 powder at 900'C to evaporate Bi2O3, place the alumina disks in this evaporated gas, and remove Bi2O3 attached to the surface of the alumina disks. When we measured the uniformity and amount of adhesion of the adherend material, we found that there was no adhesion to the adherend material, and when we examined the distribution of the adhesion amount, the standard deviation value was 0.06y.

The average amount of Bi2O3 deposited on the alumina disk was 0.1y. In Examples 1 and 2 described above, an iron ball was used as the object that is magnetically attracted, but other objects that are magnetically attracted include metals such as nickel and cobalt, ceramics such as ferrite, or magnetic materials. It may be a composite material such as rubber, and in short, any material that is magnetically attracted may be used.

Further, the shape is not limited to a sphere, but may be a polyhedron such as a tetrahedron or a hexahedron. Furthermore, the size is determined by considering the size of the object to be coated, for example, in the above example, an alumina ball,
Considering the size of the alumina disk, the surface of the object to be coated is covered with a large number of magnetically attracted objects during the mixing process, and these objects come into contact with the surface of the object evenly. That's fine. Furthermore, in order to increase the durability of the surface of an object that is attracted by magnetism, the surface of the object may be treated with synthetic resin, rubber, glass, etc. to the extent that magnetism is permeable. Furthermore, although alumina, which is an insulating material that is not attracted to magnetism, has been described as the object to be coated, other materials such as dielectric porcelain, piezoelectric porcelain, and semiconductor porcelain can also be applied.

For example, when forming a solid green layer made of metal oxides such as PlO, Bi2O3, CuO, etc. at the grain boundaries of semiconductor ceramics, such as in grain boundary insulated semiconductor ceramic capacitors, these pastes are attached to the ceramic surface. After that, it is heated and diffused into the interior of the porcelain. By this method, it is possible to deposit the appropriate amount evenly on the porcelain surface, and a grain boundary insulated semiconductor ceramic capacitor with small variations in characteristics can be obtained. In addition to the above, it goes without saying that it can also be applied to objects that can be separated from magnetically attracted objects, such as synthetic resins, rubber, glass, etc., when uniformly coated on their surfaces. Furthermore, when forming a circuit pattern on a substrate according to the intended use, pattern formation is also possible by applying this method through a mask having the desired circuit pattern. As the coating material, other general electrical materials such as conductive materials, resistance materials, and insulating materials may be used, and these may be used in the form of a paste.

Furthermore, in order to uniformly apply and diffuse the coating material onto the object to be coated, heat treatment was performed in Examples 1 and 2 described above, but if ultrasonic vibrations were applied or the coating material came into contact with moisture, it would deliquesce. If it can be diffused, it may be treated in a humid environment.

Claims (1)

[Claims] 1. A coating material is attached to the surface of an object that is magnetically attracted to form an attached body, this attached body is mixed with an object to be coated that is not magnetically attracted, and the coating material on the surface of the attached body is applied to the surface of the object to be coated. A method for applying a coating material, which is characterized in that the coating material adhered to the object to be coated is diffused while uniformly adhering to the object, and then the magnetically attracted object is attracted by magnetic force and separated from the object to be coated. .