Process for reworking circuit boards

This invention relates to printed circuit boards and, more particularly, to a machine and process for reworking defective printed circuit boards whose vias and plated through holes (PTHs) have become plugged by excessive solder. A method and apparatus is described for reworking a printed circuit boa...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Card, Jr., Norman A, Ergler, James M, Herard, James D, Kasperek, Paul R, McKinley, Richard S, Woan, Der-jin
Format: Patent
Sprache:eng
Online-Zugang:Volltext bestellen
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:This invention relates to printed circuit boards and, more particularly, to a machine and process for reworking defective printed circuit boards whose vias and plated through holes (PTHs) have become plugged by excessive solder. A method and apparatus is described for reworking a printed circuit board having plugged vias and plated through holes. The printed circuit board, supported by a movable local support, is heated from only the bottom side by a heating device near the area on the PCB that contains the plated through hole or holes to be reworked. The heating device is removed when the solder in the plugged PTH is completely melted. At that time, blast air is turned on to remove and blow off the excess solder in the PTH. The compressed air is more effective in displacing the molten solder than is vacuuming, and has less chance of damaging the PCB than do conventional reworking methods, due to the non-contact nature of the invention.