APPENDIX E: GUIDELINES FOR REFLOW SOLDERING
UNIFLOW
®
4 PULSED HEAT CONTROL
990-908 E-5
5
A. A smaller screen aperture can provide 40% solder coverage of pad.
B. Shows an alternate screen design.
C. Resulting solder deposit prior to the reflow (IR) process.
D. Solder is spread evenly across pad after the reflow (IR) process. Note smaller height profile.
PAD SIZE AND
PITCH
Mm/ inches
TARGET SOLDER
VOLUME
mm³ / inches
SCREEN THICKNESS
Microns / inches
OPENING CHEM.NI/AU
HOT AIR LEVEL
mm / inches
Cu PASSIVE / PALLADIUM
mm / inches
Pad size
0.4 x 3.2mm
0.016 x 0.126”
Pitch – 0.8 mm 0.031”
0.02 – 0.03mm
0.00079 – 0.0012”
100 micron / 0.004” 0.36 x 1.2 / 0.014 x 0.047 0.36 x 1.6 / 0.014 x 0.063
150 micron / 0.006” 0.30 x 1 / 0.012 x 0.039 0.30 x 1.2 / 0.012 x 0.047
175 micron / 0.007” 0.26 x 1/ 0.010 x 0.039 0.26 x 1.2 / 0.010 x 0.047
Pad size
0.8 x 5.5 mm
0.031 x 0.216”
Pitch – 1.5
0.059”
0.07 – 0.10 mm
0.0028 – 0.0039”
100 micron / 0.004” 0.74 x 1.9 / 0.029 x 0.075 0.74 x 2.7 / 0.029 x 0.106
150 micron / 0.006” 0.6 x 1.5 / 0.024 x 0.059 0.6 x 2.2 / 0.024 x 0.086
175 micron / 0.007” 0.5 x 1.6 / 0.020 x 0.063 0.5 x 2.3 / 0.020 x 0.091
200 micron / 0.008” 0.4 x 1.7 / 0.016 x 0.067 0.4 x 2.5 / 0.016 x 0.098
Pad size
0.8 x 4.5 mm
0.031 x 0.177”
Pitch 1.6 mm
0.063”
0.057 – 0.08 mm
0.002 – 0.0032”
100 micron / 0.004” 0.7 x 1.6 / 0.028 x 0.063 0.7 x 2.3 / 0.028 x 0.091
150 micron / 0.006” 0.6 x 1.3 / 0.024 x 0.052 0.6 x 1.8 / 0.024 x 0.071
175 micron / 0.007” 0.5 x 1.3 / 0.020 x 0.052 0.5 x 1.8 / 0.020 x 0.071
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