pnx8526 NXP Semiconductors, pnx8526 Datasheet - Page 58

• Manufacturer Part Number: pnx8526
• Description: Programmable Source Decoder With Integrated Peripherals
• Manufacturer: NXP Semiconductors

Philips Semiconductors
15. Soldering
9397 750 15101
Product data sheet
15.2.1 Soldering by dipping or by solder wave
15.2.2 Manual soldering
15.3.1 Reflow soldering
15.1 Introduction
15.2 Through-hole mount packages
15.3 Surface mount packages
This text gives a very brief insight to a complex technology. A more in-depth account of
soldering ICs can be found in our Data Handbook IC26; Integrated Circuit Packages
(document order number 9398 652 90011).
There is no soldering method that is ideal for all IC packages. Wave soldering is often
preferred when through-hole and surface mount components are mixed on one
printed-circuit board. 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.
Driven by legislation and environmental forces the worldwide use of lead-free solder
pastes is increasing.
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
printed-circuit board has been pre-heated, forced cooling may be necessary immediately
after soldering to keep the temperature within the permissible limit.
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.
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 methods exist for reflowing; for example, convection or convection/infrared
heating in a conveyor type oven. Throughput times (preheating, soldering and cooling)
vary between 100 seconds and 200 seconds depending on heating method.
Typical reflow peak temperatures range from 215 C to 270 C depending on solder paste
material. The top-surface temperature of the packages should preferably be kept:
•
below 225 C (SnPb process) or below 245 C (Pb-free process)
– for all BGA, HTSSON..T and SSOP..T packages
Rev. 02 — 11 July 2005
Programmable source decoder with integrated peripherials
© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
stg(max)
PNX8526
). If the
58 of 65