2000 Sep 07

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Philips Semiconductors

Preliminary specification

Universal Timeslot Interchange

SC2000

Suitability of surface mount IC packages for wave and reflow 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”.

2. 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).

3. 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.

4. Wave soldering is only suitable for LQFP, TQFP and QFP 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.

5. 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.

PACKAGE

SOLDERING METHOD

WAVE

BGA, LFBGA, SQFP, TFBGA

not suitable

suitable

HBCC, HLQFP, HSQFP, HSOP, HTQFP, HTSSOP, SMS

suitable

suitable

suitable

LQFP, QFP, TQFP

suitable

SSOP, TSSOP, VSO

suitable