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Browse Prior Art Database

Thermal Isolation Bushing for In-Situ Direct-Chip-Attach Reflow

IP.com Disclosure Number: IPCOM000120081D
Original Publication Date: 1991-Mar-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 28K

Publishing Venue

IBM

Related People

Christie, WR: AUTHOR [+2]

Abstract

Disclosed is a retrofit part that allows in-situ reflow of Direct-Chip-Attach for placement or rework using heated air or nitrogen. This retrofit part of "Thermal Isolation Bushing" inserts into the end of the vacuum pickup and prevents the heat in the chip from dissipating into the stainless steel of the vacuum pickup. See the figure.

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This is the abbreviated version, containing approximately 100% of the total text.

Thermal Isolation Bushing for In-Situ Direct-Chip-Attach Reflow

      Disclosed is a retrofit part that allows in-situ reflow
of Direct-Chip-Attach for placement or rework using heated air or
nitrogen. This retrofit part of "Thermal Isolation Bushing" inserts
into the end of the vacuum pickup and prevents the heat in the chip
from dissipating into the stainless steel of the vacuum pickup.  See
the figure.

      The advantage of using the thermal isolation bushing is,
instead of dropping the chip onto the target, you can apply pressure
to the chip during reflow, thus assuring that more C4 solder bumps
(leads) are in contact with the printed circuit card pads, resulting
in better yield.

      VESPEL* material was chosen for the thermal isolation bushing
because of its dimensional stability at higher temperatures.  This
concept was demonstrated on a hot air rework tool, and will apply to
any hot air local area reflow device using a vacuum pick-up to hold
the chip or component.
*  Trademark of E. I. du Pont de Nemours & Co.