Appendix A: SMT Assembly Application Note
1.0 Solder Pad, Mask and Metal
Metal Stencil
For Solder
Paste Printing
1.2 Recommended Metal Solder Stencil Aperture
It is recommended that a 0.11 mm (0.004 inches) thick
stencil be used for solder paste printing. Aperture
opening for shield pad is 0.6mm x 0.71mm. This is to
ensure adequate printed solder paste volume and no
shorting.
Aperture
Opening
Land
Pattern
0.11
Stencil
Aperture
Solder
Mask
PCBA
Aperture Opening
3.31
Unit: mm
1.7
Figure A3. Solder stencil aperture
1.3 Adjacent Land Keep-out and Solder Mask Areas
Figure A1. Stencil and PCBA
Adjacent land keep-out is the maximum space occupied
by the unit relative to the land pattern. There should be
no other SMD components within this area.
Soldering
Terminal
1.1 Recommended Land Pattern
C
L
1.00
The minimum solder resist strip width required to avoid
solder bridging adjacent pads is 0.2 mm.
Note: Wet/Liquid Photo-Imageable solder resist/mask is recommended.
2.7
0.71
0.945
1.89
Aperture
Opening
0.71
0.50
2.00
Unit: mm
Tolerance: +/- 0.2
Mounting
Center
4.31
0.60
0.60
Unit: mm
0.2 MIN.
Figure A2. Recommended Land Pattern
Figure A4. Adjacent land keepout and solder mask areas.
0
AVAGO [ AVAGO TECHNOLOGIES LIMITED ]
