TDA9850T Philips Semiconductors, TDA9850T Datasheet - Page 27

• Manufacturer Part Number: TDA9850T
• Description: I2C-bus controlled BTSC stereo/SAP decoder
• Manufacturer: Philips Semiconductors

Philips Semiconductors
SOLDERING DIP, SDIP, HDIP, DBS and SIL
Introduction
There is no soldering method that is ideal for all
IC packages. Wave soldering is often preferred when
through-hole and surface mounted components are mixed
on one printed-circuit board. However, wave soldering is
not always suitable for surface mounted ICs, or for
printed-circuits with high population densities. In these
cases reflow soldering is often used.
This text gives a very brief insight to a complex technology.
A more in-depth account of soldering ICs can be found in
our “IC Package Databook” (order code 9398 652 90011).
Soldering by dip or wave
The maximum permissible temperature of the solder is
260 C; solder at this temperature must not be in contact
with the joint for more than 5 seconds. The total contact
time of successive solder waves must not exceed
5 seconds.
The device may be mounted to the seating plane, but the
temperature of the plastic body must not exceed the
specified storage maximum. If the printed-circuit board has
been pre-heated, forced cooling may be necessary
immediately after soldering to keep the temperature within
the permissible limit.
Repairing soldered joints
Apply a low voltage soldering iron (less than 24 V) to the
lead(s) of the package, below the seating plane or not
more than 2 mm above it. If the temperature of the
soldering iron bit is less than 300 C it may remain in
contact for up to 10 seconds. If the bit temperature is
between 300 and 400 C, contact may be up to 5 seconds.
SOLDERING SO
Introduction
There is no soldering method that is ideal for all
IC packages. Wave soldering is often preferred when
through-hole and surface mounted components are mixed
on one printed-circuit board. However, wave soldering is
not always suitable for surface mounted ICs, or for
printed-circuits with high population densities. In these
cases reflow soldering is often used.
This text gives a very brief insight to a complex technology.
A more in-depth account of soldering ICs can be found in
our “IC Package Databook” (order code 9398 652 90011).
1995 Jun 19
I
2
C-bus controlled BTSC stereo/SAP decoder
27
Reflow soldering
Reflow soldering techniques are suitable for all
SO packages.
Reflow soldering requires solder paste (a suspension of
fine solder particles, flux and binding agent) to be applied
to the printed-circuit board by screen printing, stencilling or
pressure-syringe dispensing before package placement.
Several techniques exist for reflowing; for example,
thermal conduction by heated belt. Dwell times vary
between 50 and 300 seconds depending on heating
method. Typical reflow temperatures range from
215 to 250 C.
Preheating is necessary to dry the paste and evaporate
the binding agent. Preheating duration: 45 minutes at
45 C.
Wave soldering
Wave soldering techniques can be used for all
SO packages if the following conditions are observed:
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.
Maximum permissible solder temperature is 260 C, and
maximum duration of package immersion in solder is
10 seconds, if cooled to less than 150 C within
6 seconds. Typical dwell time is 4 seconds at 250 C.
A mildly-activated flux will eliminate the need for removal
of corrosive residues in most applications.
Repairing soldered joints
Fix the component by first soldering two
diagonally-opposite end leads. Use only a low voltage
soldering iron (less than 24 V) 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 at
between 270 and 320 C.
A double-wave (a turbulent wave with high upward
pressure followed by a smooth laminar wave) soldering
technique should be used.
The longitudinal axis of the package footprint must be
parallel to the solder flow.
The package footprint must incorporate solder thieves at
the downstream end.
Preliminary specification
TDA9850