DE1596811A1 - Glass-mica semiconductor and process for its manufacture - Google Patents

Description

HD rCDUADh DAT7CI 68 MAN N HEIM, May 28, 1966

UK. V ^ t KtIAKU KA I ZtL Seckenheimer Str.36a Telephone 46315

PATENT ADVOCATE 'Ί 5 3 t> ö I | , ·, _{((Llk |} , _ktill , _lhAllÄNftBM

Bon ki DtUt *** Bank MaMtIwIm No. 35i »5

GENBRAL ELECTRIC COMPANY

1 River Road

Sohenectady, New York / USA.

Glass-mica semiconductor and process for its manufacture.

The present invention relates to glass-bonded mica and in particular to the use of semiconducting glass in glass-bonded mica bodies or porous bodies.

Glass-bonded mica is a widely used building material, for example for electronic high-voltage parts of high-vacuum tubes, in which it is used to hold metal parts together. Furthermore, Sr can be easily machined into complicated geometrical shapes and well machined.

However, the previously known glass-bonded mica is .iuun not entirely satisfactory when used in environments where it has been exposed to prolonged exposure Exposed to electrons. As a result of such irradiation, the state of glass-bonded mica became the Technology found that ar has the disadvantage of building up electrical charges and then generating an electrical

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see causing punch. An attempt at this disadvantage To overcome this was done by coating the glaf bound mica elements with a material such as tin oxide, with the intention of protecting them against a To protect charge formation, however, this increases the manufacturing costs considerably, and in this way there is no complete solution of the problem achieved.

It has now been found, surprisingly, that glass-bonded mica bodies or molded bodies which are able to withstand long exposure to electrons can be produced by changing the glass content compared to the known elements by now using it as a binding material semiconducting glasses used.

Since the glass parts of the glass-bonded mica body are in constant contact with one another, they each conduct electricity Charge through the gauaen body and thus allow a Discharge of the charge while preventing an electrical view Breakthrough.

As described in detail below, the properties, in particular the resistance of the resulting body, are determined by varying the ratio J _; as ,,; limmer or by varying the resistance of the glass: ni \. ^ ö dar selection of glasses with different resistances, oescektiven.

In short, the conduction in these glasses is entirely electronic and not ionic; the resistance of the glasses used can be between ΙΟ ⁴ "and 10 ohm-cm, preferably between ICr and 10 ohm-cm.

Semiconducting glasses have already been proposed to Eich, whereby

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many of these glasses are called multi-component glasses are which, in addition to the glass network forming component, a glass network modifying component and an or contain several oxides of polyvalent metals. The network modification component can also consist of an alkaline earth metal oxide, but must then in any case in one Amount of 30 to 60 mol #, based on the weight of the glass body or the glass mass, be present. It can be a Part or all of the alkaline earth metal oxide be replaced by the oxide of a polyvalent metal, which two performs important punctures, namely a change in value the metal ions in the glass with the achievement of the new electronic conduction effect and the.! function of the necessary Glass network modification bed part.

These glasses also generally contain necessary a network image in shape due to the way they are made of a silicate, phosphate or germanate and a network modifying component, that of calcium oxide, barium oxide, strontium oxide, uagnesium oxide or a mixture of two or there is more of these oxides or one or more oxides of polyvalent metals. When using magnesia or calcium oxide and it is necessary to create a homogeneous body the non-smellability of the network modification components Overcoming with network images is another component, such as aluminum oxide or potassium oxide an essential part of the overall composition. The additive which achieves the miscibility is preferably in one Amount used that is between about 1 mol% and 5 mol%, based on the finished glass composition, lies; this additive can be added to the raw mixture of oxides before the heating stage be incorporated.

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On the other hand, it can also be added if the Basic components of the glass are in the molten state are located.

In the case of the subject matter of the invention, the mica used can be a any natural or synthetic mica or a mixture of different mica, with muscovite mica is preferable. The mica is preferably in the form of flakes or bits of shape and size used, which is common in the production of glass-bonded mica bodies of the prior art. So can It is advantageous to employ the mica in the forms described in U.S. Patent 3,131,114. the The amount or the proportion of mica used is left to the choice of the manufacturer, with the resistance value of the End product through the ratio of glass / mica and the resistance value of the semiconducting glass used is determined.

The semiconducting glass used according to the invention can are in the physical form that is generally used in the manufacturing process of glass-bonded mica bodies or mold bodies of the prior art is used. Preferably the glass is in the form of finely divided pieces -200 mesh (Tyler standard) used so that mixing with the mica sheets to form a uniform composition is favored.

The new glass-mica body or molded body of the present 'Invention are produced by a process that consists in first dividing the semiconducting glass into finely divided

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Form is mixed with the mica flakes and then the The resulting, essentially homogeneous mixture is pressed into the desired shape. The glass and the mica become generally advantageously mixed in dry form, albeit with the use of appropriate mixing devices wet mixing may also be indicated.

Slices were made by hand mixing muscovite mica and semiconducting glass (P2O5-V ^ Oc) in a weight ratio of 1: 1 a diameter of 5 cm and a thickness of 1.5 mm. Both the glass and the mica were dry and had a size of -100 mesh (Tyler standard). The preformed powdery mixture was then pressed into the final shape at a pressure of 700 kg / cm. The resulting Slices were mechanically stable, they could easily be machined, drilled and cut without any signs of breakage will. A 100 hour application of 6 volt DC potential did not show any signs of electrolysis, thus confirming the semiconducting nature of the composition.

When proportional amounts are stated in this description and the claims, the former relate to the weight.

/ Patent application

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Claims (3)

Claims 1.) Semiconducting glass-mica body or molded body, characterized in that it consists of mica and electronically conductive glass, these components being connected to form a solid body and the glass having a resistance value between 10 ⁴ and 10 ¹² ohms at normal temperature -cm owns. 2.) Semiconducting glass-mica body or shaped body according to claim 1, characterized in that the proportional amounts of the electronically conductive glass and the Glimmers are about 1: 1. 3.) A method for producing a semiconducting glass-bonded mica body or shaped body, characterized in that that one particles of electronically conductive glass, which at ordinary temperature an electrical resistance θα 12
value of 10 * to 10 ohm-cm, mixed with finely divided mica and then the homogeneous mixture on a mechanically strong and easily workable body baw. Molded body of the desired shape is pressed. 109809/0362