ST Micro announces more CMOS Image Sensor Packaging Capacity with TSV

ST enters CIS camera market
place with 3D TSV technology

ST’s claims its latest 2M pixel
mobile-phone camera module VD6725 is the worlds smallest
single-chip camera sensor for mobile applications.

The VD6725 is available in ST’s TSV
(Through Silicon Via) wafer-level package, which enables the
production of reflowable camera modules. These are soldered
directly on the phone motherboard, which saves cost, space and time
compared with the process of fixing traditional camera modules in
the board socket. ST is one of the very few companies that have
reflowable camera modules in production. Volume production is
scheduled for the end of June. Unit pricing is in the $2 range,
depending on the production period and quantities.

More pre conference info
from the 3D IC Integration sessions at the March 2008 IMAPS Device
Packaging Conference

The upcoming IMAPS Device Packaging
Conference will have several papers from Chester Balut, Pedro Jorge
and the DuPont Electronics team dealing with using dry film
photoresist for 3D IC integration and copper pillar metallization
schemes.

My recollection is that dry film was
an integral part of the FCT (Flip Chip Technologies) licensed
process technology for redistribution and solder paste bumping
developed by Pete Elenius and his group 10+ years ago. Point is
that the material has proven its stripes commercially and is being
used by nearly all the bump / WLP processes in Taiwan and Korea
(since all of them licensed the old FCT process). Their copper
pillar technology is being developed with Alan Huffman at Research
Triangle Institute. They examined 75, 100 and 120 um dry film and
were able to plate up very respectable copper studs. Huffman says
“…the key to useing such dry film materials is that the
processing time is very short when compared to comparable thickness
single spin photoresist (i.e. bake time exposure time etc.)…thats
the key ! “

This group has also studied the use
of dry film photoresist to “tent” TSV while other
processes are underway. By controlling polymer flow during
lamination with temperature, pressure and speed, dry film is
capable of applying a uniform layer of photoresist on wafers with
TSV. This ends up being a highly useful processing step which
allows other fabrication to be done with open blind vias without
getting process chemicals into the holes. I’m sure a lot of
you out them can conceive of unique processes that this would allow
in a 3D process sequence, I know I can.

For more information on using dry
film photoresist for 3D processing see the full papers at the IMAPS
conference. For all the latest on 3D integration and other advanced
technologies stay linked to Perspectives From the Leading
Edge……..