Browse Prior Art Database

Vapor Phase Rework Fountain

IP.com Disclosure Number: IPCOM000109108D
Original Publication Date: 1992-Jul-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 1 page(s) / 53K

Publishing Venue

IBM

Related People

Bonnell, RE: AUTHOR [+2]

Abstract

The disclosed vapor phase rework fountain provides a means to remove/replace PTH components with no additional copper dissolution and reduced thermal stresses to the Printed Circuit Board (PCB) and component. This vapor phase tool combines the advantages of a solder fountain with those of a vapor phase tool.

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Vapor Phase Rework Fountain

      The disclosed vapor phase rework fountain provides a means to
remove/replace PTH components with no additional copper dissolution
and reduced thermal stresses to the Printed Circuit Board (PCB) and
component.  This vapor phase tool combines the advantages of a solder
fountain with those of a vapor phase tool.

      The tool (see Figure) is a vapor phase rework tool which
functions similarly to a solder fountain by applying localized
heating to the bottom side of the PCB.  This tool is basically a
bowl-shaped main chamber with a cone-shaped chimney.  The cone-shaped
chamber directs the majority of the vapor up the cone to the chimney
where it is recondensed at the cooling coils until a rework cycle is
needed.  The cold water is then turned off to the chimney coils and
the block valve springs open allowing the chimney coils to quickly
drain or the chimney raised to a level bypassing the coiling coils.
The vapor then flows up the chimney and heats the bottom surface of
the card.  The excess vapor is held in the main chamber and
recondensed.  The recaptured vapor and the condensate from the card
surface will drip back down into the chimney or into the bottom of
the main chamber to be reboiled.  The overall process can be
monitored using the thermal couples shown in the Figure.  The main
chamber is ringed with an additional set of cooling coils to maintain
the vapor level in this zone and also help in the reclamation.

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