SU1719362A1 - Ceramic body for making high-frequency insulators - Google Patents

Abstract

The invention is expedient to use in electronic equipment in the manufacture of insulating parts of housings of semiconductor EHF devices. The purpose of the invention is to reduce the dielectric constant and sintering temperature of the material. The goal is achieved by the fact that the ceramic mass has the following composition, wt.%: Alumina (2-A12Oz) 50-65, diopside 25-40, silica-silica sol 1-7; water soluble salt of manganese 1-3. Products from this mass have a dielectric constant value of e 6-7; loss tangent 2.5-3.0-10; bending strength 280-300 MPa; The fracture toughness coefficient Kic is 2.6-2.9 mP / m3 / 2 and the sintering temperature is 1350-1400 ° C. 2 tab. 00 s

Description

The invention relates to compositions of ceramic masses for the manufacture of high-frequency products used in electronic engineering and as insulating elements of semiconductor microwave devices.

The purpose of the invention is to reduce the dielectric constant and sintering temperature.

The goal is achieved by the fact that the composition of the ceramic mass includes diopside (CaMgSteOe) in amounts of 25-40%, and as glass and mullite-forming additives include silica sol in a water-soluble salt of divalent manganese in the following ratios of components, wt.%:

Alumina (a) 50-65

Diopside (CaMgSi20e) 25-40

Silica sol

(in terms of SIO2) 1-7

Water soluble salt

manganese (in terms of

on MpO) 1-3

The introduction of pure diopside mass makes it possible to obtain a dielectric constant in the range of 6.5-7.0, with a loss value of tg b 3, and in combination with the addition of sol oxide and manganese salts, sintering of the material is achieved at 1350-1400 ° C while maintaining high strength.

In order to reduce the dielectric constant, it is necessary to reduce the content in the mass of Al203. but it requires the introduction of such an addition ™ &

x

NO

S Oh U

which does not lead to a sharp decrease in mechanical strength. Thus, an increase in the diopside content in the mass of more than 40% leads to a decrease in the mechanical strength and the viscosity coefficient of the stress. A decrease in the dioxide content of less than 25% leads to an increase in the dielectric constant (e g7), and also leads to an increase in the sintering temperature (Tspek. 1450 ° C). Also, an increase in the sintering temperature is caused by a decrease in the content in the MnO mass of less than 1%, and with an increase in its content by more than 3%, an increase in the dielectric constant and losses is observed. The silica sol promotes the formation of mullite crystals, which reinforce the glass phase and thereby increase its strength. But when its content is more than 7 wt.%, It leads to a decrease in the coefficient of fracture viscosity; this is also observed when its content decreases to less than 1%.

In tab. 1 shows the composition of the ceramic mass, and table. 2 - material properties corresponding to these compositions.

PRI me R. Alumina with a-А120з content of about 100%, diopside with an impurity content of iron oxides of no more than 0.1%, alkaline oxides no more than 0.01%, silica sol and water-soluble manganese salt (for example, MnCte) are taken as starting materials. .

Components before mixing grind in a ball mill to the grain size

10-20 µm, then dosed in the proportions given in table. 1. and mix thoroughly, then granularit to a grain size of 0.5-1.0 mm. The granules are dried at 300 ° C, then calcined in air to 900 ° C, and above 900 ° C in hydrogen. The resulting spec is ground in a ball mill to a particle size of 1-5 microns.

A slip is prepared from the obtained powder with the addition of 12-15% paraffin to the mass, and then products of the desired shape and size are made from the slip by hot-casting under pressure, for example, in sleeves up to 0.6 mm in diameter and up to 0 in height. 4 mm. The products are calcined in 2 stages up to 900 ° C in air, in higher and up to 1350-1400 ° C in a hydrogen atmosphere.

Claims (2)

The exact value of the firing temperature, as well as the properties of products depending on the composition of the mass are given in table. 2. Claims of the Invention Ceramic mass for the manufacture of high-frequency products, including AlaOa, SlOa and compounds of Ca, Md. Mp, O t-l and tea-box, so that, in order to reduce the dielectric constant and sintering temperature, the mass contains S102 as a sol, Ca and Mg compounds are in the form of diopside, and Mn is in the form of MnCte at the next the following content of components, wt.%: A1AOZ.-50-65 Sol SlOa1-7 Diopeid25-40 MPSL (in terms of MpO) 1-3 Table 1 Specifications PrototypeToption tlEZDZIIIIIZr PT 8 Sintering temperature. 15301350 1350P50MCHO ibnn Tinn tin 7G; G Flexural strength, NPA Coefficient of durability Id raeruini K ,,,, ml / and Dielectric permeability, C (10 GHz) 8.0-10.1 6.56.66.76.7 The tangent of the dielectric angle at T350 1J50 1350 1350 1400I001 001 00 280280280280290290290300 2 62 72-7гЛ2.82.92,93,0 6.86.96.97.0 losses at -,. ™ .G: 1. 3 ° 3 ° 2-5 2.5 2.5 2.5 2.5 2.5 2.5 Table 2 The composition of the mass