NXP Semiconductors PCA9665 - Manual (Page 83)

PCA9665_2 © NXP B.V. 2006. All rights reserved.
Product data sheet Rev. 02 — 7 December 2006 83 of 91
NXP Semiconductors
PCA9665
Fm+ parallel bus to I 2 C-bus controller
16. Handling information
Inputs and outputs are protected against electrostatic discharge in normal handling.
However, to be completely safe you must take normal precautions appropriate to handling
integrated circuits.
17. Soldering
17.1 Introduction
There is no soldering method that is ideal for all surface mount IC packages. Wave
soldering can still be used for certain surface mount ICs, but it is not suitable for fine pitch
SMDs. In these situations reflow soldering is recommended.
17.2 Through-hole mount packages
17.2.1 Soldering by dipping or by solder wave
Typical dwell time of the leads in the wave ranges from 3 seconds to 4 seconds at 250
°
C
or 265
°
C, depending on solder material applied, SnPb or Pb-free respectively.
The total contact time of successive solder waves must not exceed 5 seconds.
The device may be mounted up to the seating plane, but the temperature of the plastic
body must not exceed the specified maximum storage temperature (T
stg(max)
). 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.
17.2.2 Manual soldering
Apply the soldering iron (24 V or less) to the lead(s) of the package, either 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 ° C and 400 ° C, contact may be up to 5 seconds.
17.3 Surface mount packages
17.3.1 Reflow soldering
Key characteristics in reflow soldering are:
• Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to
higher minimum peak temperatures (see
Figure 49 ) than a PbSn process, thus
reducing the process window
• Solder paste printing issues including smearing, release, and adjusting the process
window for a mix of large and small components on one board
• Reflow temperature profile; this profile includes preheat, reflow (in which the board is
heated to the peak temperature) and cooling down. It is imperative that the peak
temperature is high enough for the solder to make reliable solder joints (a solder paste
characteristic). In addition, the peak temperature must be low enough that the