2004 Mar 01
74
Philips Semiconductors
Product specification
Digital video encoder
SAA7102; SAA7103
If wave soldering is used the following conditions must be
observed for optimal results:
•
Use a double-wave soldering method comprising a
turbulent wave with high upward pressure followed by a
smooth laminar wave.
•
For packages with leads on two sides and a pitch (e):
– larger than or equal to 1.27 mm, the footprint
longitudinal axis is preferred to be parallel to the
transport direction of the printed-circuit board;
– smaller than 1.27 mm, the footprint longitudinal axis
must be parallel to the transport direction of the
printed-circuit board.
The footprint must incorporate solder thieves at the
downstream end.
•
For packages with leads on four sides, the footprint must
be placed at a 45
°
angle to the transport direction of the
printed-circuit board. The footprint must incorporate
solder thieves downstream and at the side corners.
During placement and before soldering, the package must
be fixed with a droplet of adhesive.
The adhesive can be applied by screen printing, pin
transfer or syringe dispensing. The package can be
soldered after the adhesive is cured.
Typical dwell time of the leads in the wave ranges from
3 to 4 seconds at 250
°
C or 265
°
C, depending on solder
material applied, SnPb or Pb-free respectively.
A mildly-activated flux will eliminate the need for removal
of corrosive residues in most applications.
14.3.3
M
ANUAL SOLDERING
Fix the component by first soldering two
diagonally-opposite end leads. Use a low voltage (24 V or
less) soldering iron applied to the flat part of the lead.
Contact time must be limited to 10 seconds at up to
300
°
C. When using a dedicated tool, all other leads can
be soldered in one operation within 2 to 5 seconds
between 270 and 320
°
C.