pnx8511 NXP Semiconductors, pnx8511 Datasheet - Page 88

• Manufacturer Part Number: pnx8511
• Description: Analog Companion Chip
• Manufacturer: NXP Semiconductors

Philips Semiconductors
14. Soldering
9397 750 12612
Product data
14.1 Introduction to soldering surface mount packages
14.2 Reflow soldering
14.3 Wave soldering
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 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. In these situations reflow soldering
is recommended.
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. Driven by legislation and
environmental forces the worldwide use of lead-free solder pastes is increasing.
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 and 200 seconds depending on heating method.
Typical reflow peak temperatures range from 215 to 270 qC depending on solder
paste material. The top-surface temperature of the packages should preferably be
kept:
Moisture sensitivity precautions, as indicated on packing, must be respected at all
times.
Conventional single wave soldering is not recommended for surface mount devices
(SMDs) or printed-circuit boards with a high component density, as solder bridging
and non-wetting can present major problems.
To overcome these problems the double-wave soldering method was specifically
developed.
If wave soldering is used the following conditions must be observed for optimal
results:
•
•
•
below 220 qC (SnPb process) or below 245 qC (Pb-free process)
below 235 qC (SnPb process) or below 260 qC (Pb-free process) for packages with
a thickness < 2.5 mm and a volume < 350 mm
Use a double-wave soldering method comprising a turbulent wave with high
upward pressure followed by a smooth laminar wave.
—for all BGA and SSOP-T packages
—for packages with a thickness tŠ 2.5 mm
—for packages with a thickness < 2.5 mm and a volume t 350 mm
thick/large packages.
Rev. 04 – 12 January 2004
3
so called small/thin packages.
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
PNX8510/11
Analog companion chip
3
so called
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