Browse Prior Art Database

Vapor Phase Chip Carrier Removal

IP.com Disclosure Number: IPCOM000052397D
Original Publication Date: 1981-Jun-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

DeBoskey, WR: AUTHOR

Abstract

Vapor-phase condensation soldering is a well-known process for joining components to printed circuit cards or boards. A direct joining of integrated circuits or leadless chip carriers may similarly be employed. During rework of defective modules, cards or boards, it is often necessary to unsolder the bonded chip carrier or integrated circuit package from the carrier. Vapor-phase desoldering can be used to avoid disadvantages associated with the more common solder removal methods, such as hot gas jets, micro flames, infrared heating, and the like. However, the hostile hot vapor environment of the vapor-phase soldering/desoldering process precludes many of the more obvious techniques for gripping and removing the part to be joined/unjoined once the solder joint has been liquified.

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Vapor Phase Chip Carrier Removal

Vapor-phase condensation soldering is a well-known process for joining components to printed circuit cards or boards. A direct joining of integrated circuits or leadless chip carriers may similarly be employed. During rework of defective modules, cards or boards, it is often necessary to unsolder the bonded chip carrier or integrated circuit package from the carrier. Vapor-phase desoldering can be used to avoid disadvantages associated with the more common solder removal methods, such as hot gas jets, micro flames, infrared heating, and the like. However, the hostile hot vapor environment of the vapor- phase soldering/desoldering process precludes many of the more obvious techniques for gripping and removing the part to be joined/unjoined once the solder joint has been liquified. Vacuum grippers and similar tools could not be used because they would cause removal of the hot vapor from its chamber. In the vapor-phase soldering process, the various parts to be joined, or separated for rework, are loaded into the saturated vapor above a boiling vessel of the heat transfer fluid. The primary working vapor is commonly covered by a secondary vapor blanket to reduce the primary fluid loss. A fully enclosed hooded hot vapor bath arrangement is provided, and the equipment precludes direct access to and/or observation of the parts. This is not a problem during the joining process but for rework by removal of already joined parts; something...