SU937425A1 - Slip for protecting ceramic capacitors and glass fpit - Google Patents

Description

The invention relates to compositions intended for the preparation of vitreous protective coatings, and can be used in radio-electronic equipment for moisture protection of the ends of ceramic blanks of monolithic capacitors. The known composition of the slurry for zaczite semiconductor devices based on glass frit containing PbO, SIC ,, B-0, ZnO, CuO, CdO and ,, 1 The closest no technical essence to the invention is a slip for protecting water-based ceramic products and glass frit, including, wt.%: PHO-75-82; ZnO 7U; B, 0-j 6.5-12; SiO, 1.5-3; A1 0.0BaO O-lt 2. The disadvantages of the known slips are insufficient sedimentation on stability and poor application of the aqueous suspension on the ceramics, which does not allow the use of the known slips in automated manufacturing processes for products that have owls, -.-; local melting of the protective coating and burning of silver contact electrodes. The aim of the invention is to increase the sedimentation stability while maintaining high electrical properties. This goal is achieved in that the slip to protect ceramic capacitors, including a glass frit based on lead oxide and water, additionally contains 2,4,6-tris- / dimethylamino (-methyl / phenol) in the following ratio of the indicated components, m / s.% : Water 20-30 2, it, 6-tris- / Dimethylamino / -methyl / phenol0, 02-0.06 Glass

Frit Else

And also that glass frit, including PbO, ZnO,, SIO and, additionally contains Cu O in the following ratio of the indicated components, wt .:

67-76

PYo

9-11

ZnO 10-12

8203

siOi 2-3

AVO 2-5.

CuO 1-2

The values of the frit components are determined by the need to maintain

Neither the ratio but the deal, 5-6.5.

In the case when the values from Pro I

Carriers 2VgO%, 910x are outside the range of 4.5-6.5, the resulting coating interacts with a ceramic capacitor material, which leads to a decrease in Rj. cover and capacitors.

2- -6-tris- / dimethyl corresponds to the empirical formula C and the structural formula

(.CH, SCH NCCHOo.

-sh

and is a clear liquid soluble in various degrees in alcohol, acetone and water and having low vapor pressure.

Introducing it into the composition of the slip provides a gel-like state of the suspension, sedimentation stability and good application to ceramics in the case of an automated process for the manufacture of products with combined operations of melting the protective coating and burning in contact silver electrodes.

The production of the proposed slip is carried out as follows.

The prefabricated glass frit is ground by wet grinding in ball mills with a M: W: B ratio of 1: 1.5:: 0.3 for 2k-kB h. 2,4,6-tris is added to the resulting suspension - / dimethylamino / -methyl / phenol in a given ratio and mix. The finished slip is used to protect the ends of ceramic products according to a process known in the ceramic industry.

Specific examples of the proposed slip are the following compositions, wt.%:

1 2 3 Glass frit 69.9 7.9b 79.98

thirty

Water

25

20

2.46-tris- / dimethylamino / -methyl / phenol 0.06 0.0 0.02

The positive effect of the introduction of 2,4,6-tris- (dimethylamino) -methyl / phenol, which consists in ensuring the sedimentation stability and good porosity of the proposed slip, is confirmed by the experimental data given in Table 1.

Table 1

Slip

Characteristic

The presence of cement sediment

Prev5 2.5

Missing 100

There is

2J. 100

The compositions of the glass frits used are listed in Table 2.

table 2

In this case, the increase in sedimentation stability and the associated improvement in the nanoscale value of the proposed slip on ceramic materials is determined by the stability of the structure, which is characterized by its stratification.

The magnitude of the stratification L is determined by the formula L, where the volume of the liquid that peels off after holding for 2 hours, and V is the volume of the suspension material.

Practical application of the slip in the production of monolithic ceramic capacitors allows to increase their electrical strength and reduce the labor intensity of manufacturing as a result of the mechanization of the process of sealing the ends.

The proposed slip provides a coating with a bond strength of at least 50 kgf / mm. Other characteristics of mechanical strength {vibro-resistant BOqTb, impact strength, cyclical effect of loads, etc.) meet the requirements with a considerable technological reserve.

The possibility of using the slurry in capacitor production is confirmed by the results of testing products, the data on which are summarized in Table 3

Table 3

Claims (2)

1. A slip to protect ceramic condensers, including a glass frit based on lead oxide and water, characterized in that, in order to increase the sedimentation stability while maintaining high electrical properties, it additionally contains 2, 6-tris / dimethylamino / methyl / phenol in the following ratio of the indicated components , wt .: Water 20-30 2,, 6-tris / Dimethylamino / -methyl / fe0, 02-0.06 nol Glass Remaining Frit 2. Glass frit, including PHO, ZnO,., and, characterized by that she $ 10 15 8 additionally contains CuO in the following ratio of the specified components in, May POH ZnO Sources of information taken into account in the examination 1, USSR Author's Certificate No., cl. From 03 To 3/10, 1971. 2. Rousse B. Glass in electronics. M., Soviet Radio, 19b9, p.291295 (prototype).