KSC-1000 Kodak, KSC-1000 Datasheet - Page 40

• Manufacturer Part Number: KSC-1000
• Description: Timing Generator Full Program-ability Through a Simple 3-wire Serial Interface Allows Maximum Flexibility in Sensor Operation.
• Manufacturer: Kodak

IMAGE SENSOR SOLUTIONS
40
PC Board Geometry and Attachment
The package is a 8mm x 8mm Micro leadframe
(MLF) package. The package itself is Lead (Pb)
free, with a Cu-alloy lead frame and pure tin
plating. The package has been qualified for both
240 C and 260 C peak temperature soldering
profiles. These higher temperature profiles are
usually associated lead (Pb) free soldering
conditions.
The package features a large exposed metal pad
on to which the silicon ASIC is attached. This
provides a low impedance ground connection
when soldered directly to a printed circuit board.
Numerous ASIC ground connections are made
between the silicon die and the exposed center
pad, therefore a good solder connection to the
back of the package is imperative for the specified
performance.
The PC board geometry specified includes a large
metallization on to which the die will be soldered.
This metallization needs to be connected to the
ground plane of the PC board. This is done by a 4
x 4 array of vias between the top metallization and
the ground plane. Each of the vias is covered with
solder mask to prevent solder from flowing into it.
If the solder flows into the via, the uniformity of the
solder bond is compromised and voids will form.
K S C - 1 0 0 0 R e v 1 . 0
w w w . k o d a k . c o m / g o / i m a g e r s
5 8 5 - 7 2 2 - 4 3 8 5
The solder connection that provides the ground
should contact the inner large exposed pad. It is
not necessary or recommended to attach the
outer ring pad to the ground plane. The solder
stencil pattern is used to define the areas where
the package is soldered to the PC board. A solder
stencil thickness of 0.125 mm is recommended for
parts with 0.5mm pitch, such as this one. Since
not enough space is available underneath the part
after
recommends that a “No Clean”, Type 3 paste be
used for mounting MLF packages.
In the following figures, the solder mask is not
defined for the perimeter pads. At this pad pitch
and size, manufacturers differ on whether they
prefer to mask each perimeter pad individually or
to open all the perimeter pads collectively within
one large rectangle. The solder mask that is
shown in the figures is to “tent” the via holes in the
center ground pad. The tenting of the via holes is
not critical. The size of the solder mask should, at
the minimum, be the larger than the via holes by
the PC board manufacturing alignment tolerance.
There will also be solder mask between the large
center ground connection and the I/O pads but this
is not explicitly shown.
E m a i l : i m a g e r s @ k o d a k . c o m
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package
manufacturer