1998 Dec 14
69
Philips Semiconductors
Preliminary specification
Economy teletext and TV microcontrollers
SAA5x9x family
18.4
Suitability of IC packages for wave, reflow and dipping soldering methods
Notes
1.
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”
For SDIP packages, the longitudinal axis must be parallel to the transport direction of the printed-circuit board.
These packages are not suitable for wave soldering as a solder joint between the printed-circuit board and heatsink
(at bottom version) can not be achieved, and as solder may stick to the heatsink (on top version).
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.
Wave soldering is only suitable for LQFP, QFP and TQFP packages with a pitch (e) equal to or larger than 0.8 mm;
it is definitely not suitable for packages with a pitch (e) equal to or smaller than 0.65 mm.
Wave soldering is only suitable for SSOP and TSSOP 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.
2.
3.
4.
5.
6.
MOUNTING
PACKAGE
SOLDERING METHOD
WAVE
REFLOW
(1)
suitable
suitable
suitable
suitable
suitable
DIPPING
Through-hole mount DBS, DIP, HDIP, SDIP, SIL
Surface mount
BGA, SQFP
HLQFP, HSQFP, HSOP, HTSSOP, SMS
PLCC
(4)
, SO, SOJ
LQFP, QFP, TQFP
SSOP, TSSOP, VSO
suitable
(2)
not suitable
not suitable
(3)
suitable
not recommended
(4)(5)
not recommended
(6)
suitable