Method and compact machine for treating printed circuit cards

Claim 1

A method of dispensing printed circuit cards in a compact machine for removing impurities from a surface of the printed cards subjected in a separate step to a soldering operation using a fluxing agent, said machine having an inlet and an outlet end section and an intermediate section having upper and lower, separated from one another, spaces, the upper of which defines a treating chamber having a plurality of successive treating zones comprising at least a washing and brushing zone, for removing impurities from the lower surface of the printed circuit cards by the action of brushes and cold solvent, and a subsequent drying zone in which the printed circuit cards are subjected to hot air flow for removing solvent therefrom, said method comprising feeding the cards through the machine sections along a horizontal transport track from the machine inlet end section to and through the machine outlet end section, providing a first closed loop within said intermediate and outlet sections for recycling solvent used in the treating chamber and containing impurities removed from the cards and collected in a trough means in the upper space of the intermediate section, said solvent with impurities therein being passed from an upstream end of the trough means to distiller means in the outlet end section of the machine for vaporizing and condensing the vaporized solvent, condensed cold solvent, substantially free of impurities, being returned to the downstream side of the trough means in the treating chamber; providing a second closed loop path in the intermediate section for said hot air flow for removing solvent from solvent wetted cards as they pass along said track through said intermediate section, said second path including a cooling means and blower means in the upper space of the intermediate section and an air compressor in the lower space thereof, solvent contained in the air being condensed in the cooling means and passed to said distiller means while the air freed of solvent is fed to said air compressor to heat the air between 0°-10° C. above the boiling point of the solvent, and supplying the thus heated air to said blower means for discharge unto the solvent wetted cards; and providing a third closed loop for distilling solvent and comprising said distiller means including a heat exchanger in a solvent tank in a lower space of the outlet end section for vaporizing solvent therein and a cooler in an upper space of the outlet end section for condensing the vaporized solvent.

Claim 2

A method of dispensing printed circuit cards in a compact machine for removing impurities from a surface of the printed cards subjected in a separate step to a soldering operation using a fluxing agent, said machine having an inlet and an outlet end section and an intermediate section having upper and lower, separated from one another, spaces, the upper of which defines a treating chamber having a plurality of successive treating zones comprising at least a washing and brushing zone, for removing impurities from the lower surface of the printed circuit cards by the action of brushes and cold solvent, and a subsequent drying zone in which the printed circuit cards are subjected to hot air flow for removing solvent therefrom, said method comprising feeding the cards through the machine sections along a horizontal transport track from the machine inlet end section to and through the machine outlet end section, providing a first closed loop within said intermediate and outlet sections for recycling solvent used in the treating chamber and containing impurities removed from the cards and collected in a trough means in the upper space of the intermediate section, said solvent with impurities therein being passed from an upstream end of the trough means to distiller means in the outlet end section of the machine for vaporizing and condensing the vaporized solvent, condensed cold solvent, substantially free of impurities, being returned to the downstream side of the trough means in the treating chamber; providing a second closed loop path in the intermediate section for said hot air flow for removing solvent from solvent wetted cards as they pass along said track through said intermediate section, said second path including a cooling means and blower means in the upper space of the intermediate section and an air compressor in the lower space thereof, solvent contained in the air being condensed in the cooling means and passed to said distiller means while the air freed of solvent is fed to said air compressor to heat the air between 0°-10° C. above the boiling point of the solvent, and supplying the thus heated air to said blower means for discharge unto the solvent wetted cards; and providing a third closed loop for distilling solvent and comprising said distiller means including a heat exchanger in a solvent tank in a lower space of the outlet end section for vaporizing solvent therein and a cooler in an upper space of the outlet end section for condensing the vaporized solvent.