Browse Prior Art Database

Hot Nitrogen Chip-Removal Nozzle

IP.com Disclosure Number: IPCOM000111856D
Original Publication Date: 1994-Apr-01
Included in the Prior Art Database: 2005-Mar-26
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Horton, RR: AUTHOR [+4]

Abstract

The hot nitrogen chip-removal nozzle permits chip removal for rework or repair. The nozzle directs hot nitrogen to the top of the chip surface to reflow the chip's lower C4 pads. The defective chip is then removed immediately via a centered vacuum tip, making a mechanical lift. An outer vacuum ring is added to the nozzle to prevent C4 solder reflow to the adjacent chip and for the prevention of seal band solder reflow and oxidation.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Hot Nitrogen Chip-Removal Nozzle

      The hot nitrogen chip-removal nozzle permits chip removal for
rework or repair.  The nozzle directs hot nitrogen to the top of the
chip surface to reflow the chip's lower C4 pads.  The defective chip
is then removed immediately via a centered vacuum tip, making a
mechanical lift.  An outer vacuum ring is added to the nozzle to
prevent C4 solder reflow to the adjacent chip and for the prevention
of seal band solder reflow and oxidation.

      In the Figure, the inner nozzle 1 and outer nozzle 2 allow hot
compressed nitrogen to be accurately directed through port 3, on top
of the chip site 4.  The hot nitrogen is then evacuated and cooled
throughout the drawn outer atmosphere caused by vacuum manifold 5.

This prevents the adjacent chip C4 pads from reflowing or seal band
reflow/oxidation.

      When the chip's C4 pads reach their reflow temperature, the
chip is drawn securely to the nozzle by an activated center cavity
vacuum 6.  The chip is totally removed from the module cavity by an
upward mechanical thrust.

      The outer and inner nozzle constructions are of rectangular,
tapered shape and are capable of accommodating various sizes of
chips.