Printed Wiring

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Printed Wiring

 

a method of wiring electronic apparatus in which the connections between electric and electronic components, including shields, are made by means of fine conductive strips with contact areas that are arranged on a printed circuit board. Printed wiring makes possible a reduction in the size and weight of apparatus and the use of mechanized and automated equipment and highly efficient processes for mass production. In addition, the reliability of the items is improved, and material outlays and labor costs are reduced.

Printed conductors are produced by etching metal-clad insulating material, by electrochemical deposition, by vacuum or cathode sputtering, by baking on conductive inks, and by electroplating, with transfer of the conducting pattern to an insulating board. The image of the printed conductors is printed on a board by photographic, offset, and screening methods, as well as molding, and embossing. Continuity of contacts between the two sides of a board is produced by plating the walls of the holes or by inserting metal tubes, which are subsequently flared and soldered. The conductors in printed wiring are usually 20–50 microns thick and 0.5–0.8 mm wide; the minimum distance between conductors is 0.3–0.5 mm. As a result of favorable heat-removal conditions, high current density (up to 30–50 amperes per sq mm) is permissible in printed conductors. Multilayer printed-circuit boards are used for microminiaturization of apparatus based on multiple-output integrated circuits, thus achieving a substantial increase in circuit density.

REFERENCES

Belevtsev, A. T. Tekhnologiia proizvodstva radioapparatury. Moscow, 1971.
Arenkov, A. B. Pechatnye i plenochnye elementy radioelektronnoi apparatury. Leningrad, 1971.

B. P. LIKHOVETSKII

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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Firan Technology Group Corporation (TSX: FTG) said that it has been awarded a new multi-year enterprise sourcing agreement from Rockwell Collins for the supply of printed wiring boards.
This test is designed to expose a processed or unprocessed printed wiring substrate to elevated temperatures and humidity while applying an electrical potential to determine the propensity for electromigration.
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