Philips Semiconductors
ISP1122A
USB stand-alone hub
Preliminary specification
Rev. 01 — 27 March 2000
44 of 48
9397 750 06986
Philips Electronics N.V. 2000. All rights reserved.
18.4 Package related soldering information
[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]
Table 35: Suitability of IC packages for wave, reflow and dipping soldering methods
Mounting
Package
Soldering method
Wave
Reflow
[1]
Dipping
Through-hole
mount
Surface mount
DBS, DIP, HDIP, SDIP, SIL suitable
[2]
suitable
BGA, LFBGA, SQFP,
TFBGA
HBCC, HLQFP, HSQFP,
HSOP, HTQFP, HTSSOP,
SMS
PLCC
[4]
, SO, SOJ
LQFP, QFP, TQFP
SSOP, TSSOP, VSO
not suitable
suitable
not suitable
[3]
suitable
suitable
not recommended
[4] [5]
suitable
not recommended
[6]
suitable
suitable