Philips Semiconductors
SC16C554/554D
Quad UART with 16-byte FIFO and infrared (IrDA) encoder/decoder
Product data Rev. 05 — 10 May 2004 51 of 55
9397 750 13132
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
• 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;
– 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 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 to 5 seconds between 270 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
.
Table 28: 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, USON, VFBGA
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
