Imaging chips with TSV announced for commercialization
The latest 3D
integration announcement details the commercialization of
CMOS image chips for portable devices.
On Oct
1st Toshiba announced that in order to enhance
competitiveness in their image sensor business they would be
bringing the manufacturing of CMOS camera modules for mobile phones
in-house.Production of the CSCM (chip scale camera module), shown
in the figure below, will start at January 2008. They will be
the first camera modules manufactured with what they are
calling TCV (Through Chip Via) or what we have come to know as
TSV (through silicon via ) technology.
The current technology is compared to the new
technology in the figure below. The new CSCM micro-camera modules
reportedly reduce the area previously required for wire
bonding the module to a substrate by mounting the components
directly on the wafer,running electrodes through the wafer and
attaching to the circuit board with solder balls. The new product
also reduces pixel size, contributing to a module size up to 64%
smaller than camera modules manufactured with the same sensors.
Toshiba notes that the application of balls of solder and heat
resistant lenses ( not affected by reflow) significantly reduces
the process time for camera mounting to the circuit boards of
mobile consumer products.
Toshiba had previously published CMOS imaging
chip packaging technology where they laser drill the back side vias
in the chip, insulate by laminating a epoxy resin sheet to fill the
vias and then reopen the vias to the backside of the contact pads
by another laser drilling operation [1]. At this time it is unknown
as to whether this process is being used in the CSCM production
announcement.
[1] M. Sekiguchi
et. al., “Novel Low Cost Integration of Through Chip
Interconnection and Application to CMOS Image Sensor”, ECTC,
2006, p. 1367.
