SU1155574A1 - Ceramic material - Google Patents

Abstract

CERAMIC MATERIAL, including magnesium titanate and titanium oxide, characterized in that, in order to reduce the temperature coefficient of the dielectric constant and increase microhardness, it additionally contains polyrite in the following ratio, wt.%: Titanium magnesium 49.5-69.4 Oxide titanium 29.7-49.5 Polyrite Oj, 8-1.0

Description

The invention relates to ceramic materials used in electronic equipment in the ultra-high frequency range, in particular for the manufacture of substrates of micropowered circuits, bases of electrical delay lines. A ceramic material made on the basis of MgDU titanate with the addition of bentonite, whose dielectric constant is equal to 19, the dielectric loss tangent is 3 X 10, the temperature coefficient of dielectric constant is 840 x 10 degrees 1. The disadvantage of this material is the high value of the temperature coefficient of the dielectric constant, which sudestvenno reduces the stability of the elements of electronic equipment in conditions of elevated temperatures. Known ceramic materials Radzomix R-02C, synthesized in the system of magnesium titanate - calcium titanate. These materials s1 have a dielectric constant of 20, a dielectric loss tangent of 2 X 10, a temperature coefficient of frequency G (-4) - (+4) 1x 10% ad 2 To the disadvantages of these materials should be attributed to low microhardness, equal to 300 kgf / mm which does not allow to achieve high surface cleanliness when machining: after polishing the plates of this material have a height of defects on the surface of 2 microns. The closest to the invention and the technical essence and the achieved result is a ceramic material containing Mg MgTiOj titanate, lanthanum oxide, Alj 0 alumina, SrOj strontium oxide. The material has the following dielectric characteristics in the microwave range: dielectric constant 16.5, dielectric triangle loss tangent 1.4 X 10, dielectric constant temperature coefficient +100 x Yu hail

The disadvantages of this material are the increased temperature coefficient of the dielectric constant, which reduces the stability of the electronic equipment in the conditions of elevated temperatures, and the low micromovement of less than 0.8 wt.% Does not affect the structure of the material and, as a result, its strength characteristics, in particular, microhardness with the introduction of polyrite in the amount of microhardness, impairing the reliability, operation of the equipment with a long service life. The purpose of the invention is to reduce the temperature coefficient of the dielectric constant and increase the microhardness of a ceramic material intended for use in electronic equipment in the ultra-high frequency range. This goal is achieved by the fact that the ceramic material, including magnesium titanate and titanium oxide, additionally contains polyrite in the following ratio of components. wt.%: Titanate 49.5-69.4 Magnesium 29.7-49.5 Titanium 0.8-1.0 Polyrite Polyrite introduced as a modifying additive is a commercially available concentrate of oxides of rare-earth elements,% by weight: cerium 50.0 lanthanum 25.0 neodymium 12.5 pp 3 eduim 12.5 Examples of the composition of the ceramic material are given in table. 1. Table 1 Titanium Magnesium Oxide Titanium Polirit

31

more gcc.% increases the material's firmness, reducing its mechanical properties.

Example. The manufacture of ceramic material.

1. Synthesis

The prepared raw materials magnesium oxide (in the form of magnesium carbonate MgC03) and titanium oxide are mixed in the stoichiometric ratio of MgO-TiOi. Mixing is carried out with a wet method in a ball mill with a material-ball ratio of water equal to 1: 1: 2 for 8-10 hours. The resulting slurry is dried in a muffle furnace to a residual moisture content of 10-12 wt.%, Rubbed through a sieve with mesh No. 012, and then subjected to heat treatment in an electric furnace at 1250 ° C for 2 hours. The synthesized magnesium titanate is ground in a ball mill to obtain a specific surface area of 40005000.

2. Production of samples.

In a ball mill using the dry method with a ratio of material ;, Rav44

No. 1: 1, mix the initial mixture composition: Titanate

Magni 49,5-, 4 Oxide

titanium 29.7-49.5 Polyrite 0.8-1.0 Samples, for example, plates measuring 60x48 mm, are formed by the method of semi-dry pressing of the mass plastified with polyvinyl alcohol of 6% concentration. The specific compaction pressure is 100 MPa. The final calcination is carried out in the temperature range of 1400-1420 ° C for 1 hour.

On fabricated samples, the Vickers microhardness was determined

on microhardometer universal metallographic microscope MEF-2. The surface cleanliness class was determined on a Tapisurf-4 profilograph-profilometer.

A comparative characteristic of ceramic materials according to the prototype and according to the invention is presented in Table. 2

Table 2

Dielectric permeability at a frequency of f 10 Hz Tangent of dielectric loss angle at a frequency of f 10 ° Hz Temperature coefficient of dielectric permeability in the temperature range (-60) - 250 ° C, degrees - 10 Microhardness, kgf / mm Surface finish class

Thus, using 55 of the invention makes it possible to obtain a dense ceramic material with a dielectric constant of 16-20, a dielectric loss tangent of 1x10, a temperature coefficient of dielectric constant in the temperature range D-60), 18.0 20.0 1 -10 1- 10 0 ± 10 0 ± 10 1050 1050

5 -1155574,

equal to (0-10 X YKgrad. The material of the proposed ceramic

It has a dense fine-crystalline material, which will ensure the extension of the treatment structure and the microhardness of the service, as well as provide a technical 1050 kgf / MMS that gives the performance and operational properties

the ability to achieve cleanliness of imaging-5 elements of the surface electronic equipment for class 14. Pri-ry.

Claims (1)

CERAMIC MATERIAL, including magnesium titanate and titanium oxide, characterized in that, in order to reduce the temperature coefficient of dielectric constant and increase microhardness, it additionally contains pyrite in the following ratio of components, May.%: Magnesium Titanate 49.5-69.4 Titanium oxide 29.7-49.5 Polishes 0j8-1.0 "yut UT SL SL M 4 *> , <ί