METHOD OF SOLDERING Russian patent published in 1997 - IPC

FIELD: production of printed circuit boards; local heating of printed circuit boards with mixed wiring including pin and planar point-to-point and surface mounted articles in different combinations on one-sided and double-sided printed circuit boards. SUBSTANCE: method of soldering articles on double-sided printed circuit board comes to determining zonal temperature distribution in heat source by means of mounted temperature sensors, determining preset soldering conditions, applying soldering paste to zone of wiring, mounting of temperature sensors in place of fitting of checked articles, mounting of preformed pin and point-to-point mounted articles into base holes, fastening the articles by means of heat insulating gasket made of raw silicone rubber composition moulded to suit shape and size of point-to-point mounted articles, turning over the printed circuit board, mounting the board on cassette locks, finish fitting of pin and point-to- point mounted articles in base holes, placing surface mounted articles on mounting flats and soldering by melting the solder. This is done by passing check printed circuit board through zones of preheating, soldering and forced cooling by gas flow whose direction coincides with direction of movement of printed circuit board in head source. Simultaneously temperature distribution diagram in places of mounting of checked articles is plotted, quality of soldered joints and articles is evaluated, and optimum conditions for carrying out soldering of standard printed circuit boards are determined. EFFECT: improved quality of soldering. 2 tbl