9397 750 12534 © Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Product data sheet Rev. 01 — 29 November 2005 16 of 20
Philips Semiconductors
PCK9448
3.3 V/2.5 V LVCMOS 1 : 12 clock fan-out buffer
12. Soldering
12.1 Introduction to soldering 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 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.
12.2 Reflow soldering
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 seconds and 200 seconds depending on heating method.
Typical reflow peak temperatures range from 215 °Cto270°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
for packages with a thickness 2.5 mm
for packages with a thickness < 2.5 mm and a volume 350 mm
3
so called
thick/large packages.
below 240 °C (SnPb process) or below 260 °C (Pb-free process) for packages with a
thickness < 2.5 mm and a volume < 350 mm
3
so called small/thin packages.
Moisture sensitivity precautions, as indicated on packing, must be respected at all times.
12.3 Wave soldering
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:
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;
9397 750 12534 © Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Product data sheet Rev. 01 — 29 November 2005 17 of 20
Philips Semiconductors
PCK9448
3.3 V/2.5 V LVCMOS 1 : 12 clock fan-out buffer
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 seconds 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.
12.4 Manual 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 seconds to 5 seconds between 270 °C and 320 °C.
12.5 Package related soldering information
[1] For more detailed information on the BGA packages refer to the
(LF)BGA Application Note
(AN01026);
order a copy from your Philips Semiconductors sales office.
[2] All surface mount (SMD) packages are moisture sensitive. Depending upon the moisture content, the
maximum temperature (with respect to time) and body size of the package, there is a risk that internal or
external package cracks may occur due to vaporization of the moisture in them (the so called popcorn
effect). For details, refer to the Drypack information in the
Data Handbook IC26; Integrated Circuit
Packages; Section: Packing Methods
.
[3] These transparent plastic packages are extremely sensitive to reflow soldering conditions and must on no
account be processed through more than one soldering cycle or subjected to infrared reflow soldering with
peak temperature exceeding 217 °C ± 10 °C measured in the atmosphere of the reflow oven. The package
body peak temperature must be kept as low as possible.
Table 12: Suitability of surface mount IC packages for wave and reflow soldering methods
Package
[1]
Soldering method
Wave Reflow
[2]
BGA, HTSSON..T
[3]
, LBGA, LFBGA, SQFP,
SSOP..T
[3]
, TFBGA, VFBGA, XSON
not suitable suitable
DHVQFN, HBCC, HBGA, HLQFP, HSO, HSOP,
HSQFP, HSSON, HTQFP, HTSSOP, HVQFN,
HVSON, SMS
not suitable
[4]
suitable
PLCC
[5]
, SO, SOJ suitable suitable
LQFP, QFP, TQFP not recommended
[5] [6]
suitable
SSOP, TSSOP, VSO, VSSOP not recommended
[7]
suitable
CWQCCN..L
[8]
, PMFP
[9]
, WQCCN..L
[8]
not suitable not suitable
9397 750 12534 © Koninklijke Philips Electronics N.V. 2005. All rights reserved.
Product data sheet Rev. 01 — 29 November 2005 18 of 20
Philips Semiconductors
PCK9448
3.3 V/2.5 V LVCMOS 1 : 12 clock fan-out buffer
[4] These packages are not suitable for wave soldering. On versions with the heatsink on the bottom side, the
solder cannot penetrate between the printed-circuit board and the heatsink. On versions with the heatsink
on the top side, the solder might be deposited on the heatsink surface.
[5] If wave soldering is considered, then the package must be placed at a 45° angle to the solder wave
direction. The package footprint must incorporate solder thieves downstream and at the side corners.
[6] Wave soldering is suitable for LQFP, QFP and TQFP packages with a pitch (e) larger than 0.8 mm; it is
definitely not suitable for packages with a pitch (e) equal to or smaller than 0.65 mm.
[7] Wave soldering is suitable for SSOP, TSSOP, VSO and VSSOP packages with a pitch (e) equal to or larger
than 0.65 mm; it is definitely not suitable for packages with a pitch (e) equal to or smaller than 0.5 mm.
[8] Image sensor packages in principle should not be soldered. They are mounted in sockets or delivered
pre-mounted on flex foil. However, the image sensor package can be mounted by the client on a flex foil by
using a hot bar soldering process. The appropriate soldering profile can be provided on request.
[9] Hot bar soldering or manual soldering is suitable for PMFP packages.
13. Abbreviations
14. Revision history
Table 13: Abbreviations
Acronym Description
ESD ElectroStatic Discharge
HBM Human Body Model
MM Machine Model
MTBF Mean Time Between Failures
LFPM Linear Feet Per Minute
LVPECL Low Voltage Positive Emitter Coupled Logic
LVCMOS Low Voltage Complementary Metal Oxide Silicon
Table 14: Revision history
Document ID Release date Data sheet status Change notice Doc. number Supersedes
PCK9448_1 20051129 Product data sheet - 9397 750 12534 -

PCK9448BD,151

Mfr. #:
Manufacturer:
NXP Semiconductors
Description:
IC CLK BUFFER 2:12 350MHZ 32LQFP
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
T/T Paypal Visa MoneyGram Western Union

Products related to this Datasheet