Brochure/Catalogue

10
Design and processing recommendations
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For optimum soldering results in the SMT process we recommend the following parameters for our THR components:
Pin header
Pins Inner diameter of
solder eyelet
D [mm]
Outer diameter of
solder eyelet
D
A
[mm]
Stencil aperture
diameter
D
SI
[mm]
Solder pin diameter
d [mm]
Solder pin
length
L [mm]
S2C-SMT 3.50 &
S2L-SMT 3.50
4–36 1.30
+0,1
2.10 1.90 1.0, octagonal 1.50
SL-SMT 3.50 2–8 1.40
+0,1
2.30 2.10 1.2, octagonal 1.50
SL-SMT 3.50 LF/RF
SL-SMT 3.50
2–8
9–24
1.50
+0,1
2.30 2.10 1.2, octagonal 1.50
SC-SMT 3.81 2–16 1.30
+0,1
2.10 1.90 1.0, octagonal 1.50
SL-SMT 5.00/5.08 2–8 1.40
+0,1
2.30 2.10 1.2, octagonal 1.50
SL-SMT 5.00/5.08 LF/F
SL-SMT 5.00/5.08
2–8
9–24
1.50
+0,1
2.30 2.10 1.2, octagonal 1.50
LSF-SMT 3.xx
LSF-SMT 5.xx
LSF-SMT 7.xx
2–12
2–8
2–6
1.10
+0,1
1.90 1.70 0.9 (0.35 x 0.8) 1.50
Stencil thickness D
S
[µm]
120–180 (continuous for all product families listed)
Solder paste grain size [µm] 20–40 = Type 3
For our SMT components, we recommend the following reow soldering prole, illustrated here with a typical characteristic
and process boundaries. In the preheating phase, the PCB and components are preheated while the solder paste is activated.
Above a temperature of 217 °C to 221 °C, the solder fuses and joins the components to the connectors on the board. The
temperature is maintained at 245 °C to 254 °C for between 10 and 45 seconds in order to ensure a secure connection. During
the cooling period the solder hardens. Stress cracks as a result of excessively rapid cooling must be avoided.
300
250
217
200
150
100
50
0
0 50 100 150 200 250 300 350
Time [sec]
Temperature [°C]
preheating
Melting point lead-free solder paste
Cooling rate:
< 6 °K/s
180 °C
190 °C
235 °C
245 °C
254 °C
approx.
60 s > 217 °C
Continuous line: Typical process
Dotted line: Process limits
Heating rate: < 3 °K/s
d
d
H
D
D
A
D
SI
D
S