The technological process steps:
1. Formation of a film of the required material on a ceramic
substrate (the coating can be single-layer or multi-layer). Most
often, a two-layer coating is formed - a thin film of the adhesive
sublayer and a film of the main functional layer;
2. Applying photoresist to the formed layer;
3. Exposure and manifestation of photoresist;
4. Chemical etching of the deposited main functional coating;
5. Removing the photoresist from the surface of the board;
6. Application of the finishing coating.
Thanks to thin-film technology, it became possible to manufacture
thin-film active and passive elements, which made it possible to
reduce the dimensions of the final electronics products and
increase their performance.
Ceramic AlN (aluminum nitride) and Al2O3 (polycor BK100) are used
as substrates;
Conductive materials are used to form the topology. The most
commonly used: Cu, Al. Thanks to thin-film technology, it is
possible to form optically transparent conductive ITO (In-SnOxide)
films.
Active and passive elements are formed from various dielectric and
conductive materials.
Metals, metal alloys and organic compounds can be used as finishing
materials. The most widely used coatings are chemical
nickel-immersion gold, immersion silver, immersion tin,
electroplating and others.
Depending on the required accuracy, the conductor-gap distance, the
type of resistor and the method of lithography are selected. The
most commonly used are photoresists and the photolithography
process.
