DFM and SMT Assembly Guideline TB-2082
Revision “H“
Copyright © Amphenol Corporation 2014 • All rights reserved Page 31 of 33
10.0 Rework Process
The rework of a NeXLev connector, for solder shorts and opens, requires that the connector be
completely removed and replaced with a new connector.
Requirements DFM Impact/Benefit
Use specialized BGA rework equipment for connector
removal and replacement, and should include thermal
profiling and temperature measurement capability.
Achieves an all-ball reflow at point of removal
without excessive heat to t he connector an d PCB, or
insufficient heat causing lifted pads.
Locate one thermal probe on top of the connector
housing during reflow profiling – It is preferred to keep
the plastic below 260C with a max allowable
temperature of 280C.
Insures against plastic over-heating and damage.
(See reflow section for m ore detail.)
Placement location/centroid of the part should be based
on the ball locations, and placed using a best-fit
alignment – see next page for best-fit alignment detail
Minimizes the percentage of ball that is off-pad.
Semi-Automated placem ent capability is preferred –
including vacuum pick-up and placement.
This will provide consistent place ments.
Split Vision alignment systems are required to allow a
ball-field best-fit alignment to PCB footprint.
Allows blind alignment of ball to pad - minimizing
placement error.
Hand/Manual placement is not recommended. Manual placement is inconsistent, and blind/housing
align does not provide the required placement
accuracy.
Using custom NeXLev nozzles is preferred for the
taller receptacles (15.5 and 23.5 mm)
Because of the higher thermal masses, more
consistent/even heat distribution is required.
Follow normal rework processes for PCB site cleaning
and prep, and reflow profile development.
Improves rework yield and insures reliable solder
joints
“Flux-only” processing is not recommended. Inconsistent amount of metal left on pad during site
prep, resulting in excessive pad co-planarity
variation – increased risk of solder opens.
Paste deposition is recommended using either an
automated dispensing system or manual micro stencils
– resulting in a 6 mil tall x 21 mil diameter deposit.
Prevents opens/shorts with high reliability solder
joints.
Re-balling of NeXLev connectors is not recommended. Re-balling processes not available for NeXLev.
The most popular rework systems, which have NeXLev custom nozzles, and have also developed a
full process for all the different sizes, include Air-Vac and VJ Electronix. For more info go to the
following Web Sites:
Air-Vac http://www.air-vac-eng.com/nozzleconnector.htm
VJ Electronix http://vjelectronix.com/index.html