SU115380A1 - The method of obtaining by sublimation in vacuum of high-resistance thin-layer resistances - Google Patents

Description

One of the known methods for producing HIGHLY IMPORTANT thin layer resistances is to apply a conductive layer on a sufficiently developed rough surface, which is usually obtained by etching the surface of a ceramic base.

It is also known to form a rough surface of the film and its subsequent calcination, providing an oxidized metal layer with a highly developed surface.

The peculiarity of the proposed method of obtaining HIGH-IMPORTANT thin-layer resistances consists in combining the formation of the said oxidized metal layer and the deposition of a conductive film, which simplifies the manufacturing technology and improves the quality of the product.

For the implementation of the proposed method, a heat-resistant metal or alloy capable of being calcined at a temperature of 700-800 ° (for example, platinum or its alloys, nichrome and a number of other metals) with the addition of a much more volatile metal (for example, aluminum cadmium).

The combined method of obtaining a developed relief of the base surface (by preliminary evaporation of an easily evaporating metal and oxidation of its condensed film) and deposition of a conductive high-resistance layer by evaporation can be performed by two formally different methods: the film of which they want to get, or by evaporation the powder of a previously prepared aluminum alloy and that high-resistance metal or alloy, Whole film you want to get.

As in that, and in another case, general evaporation is carried out in a combined way. At first, a heat-resistant metal with a ssgvvka of more easily volatile megl is heated to a temperature that only sublimates an easily evaporated additive, and then to

higher temperature at which evaporation of the remaining part of the alloy occurs. Then, the combined layer run flat onto the base is calcined at a temperature of about 100 °, at which the metal of the intermediate layer (for example aluminum) is oxidized, and the resistance of the wire going to the layer rises.

For the combined evaporation of the mixtures under consideration, far from all possible proportions between aluminum and high metal or alloy are suitable. Excessive amount of low-melting metal (aluminum, zinc, or others) leads to such a powerful development of the surface relief that, on the ground wire located above it, gaps and ruptures can form. The electrical resistance becomes very negative and the electrical strength of the film decreases (large irreversible changes in the resistance value occur under electrical load). Good results, with reliable reproducibility of the electrical characteristics of the layer, can be obtained when the amount of aluminum in the evaporated alloy (or mechanical mixture) is not more than 20% in the case when

the weight of the remainder (high-resistance metal or alloy) is approximately 5 g / cm. For all other possible options, this ratio should be chosen experimentally, depending on the specific gravity of a high-resistance metal or alloy.

Subject invention

The method of sublimation of thin-walled resistances in vacuum, containing an intermediate wire conductor w; by their layer and insulating base, an oxidized metal film with a highly developed surface, which is much easier The evaporating metal (for example, aluminum, zinc, cadmium) is first heated to a temperature that only sub-additive can sublimate, and then to a higher temperature. urs and then applied onto the base layer composite is calcined at elevated temperature to oxidation of the intermediate metal film.