Ublox NORA-W36 Series, System Integration Manual

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NORA-W36 series - System integration manual
UBX-22021120 - R01 Handling and soldering Page 29 of 48
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5.3 Reflow soldering process
NORA-W36 series modules are surface mounted devices supplied in a Land Grid Array (LGA) package
with gold-plated solder lands. The modules are manufactured in a lead-free process with lead-free
soldering paste.
The thickness of solder resist between the host PCB top side and the bottom side of the NORA-W36
series module must be considered for the soldering process.
NORA-W36 modules are compatible with the industrial reflow profile for common SAC type RoHS
solders. No-clean soldering paste is strongly recommended. The reflow profile is dependent on the
thermal mass over the entire area of the fully populated host PCB, the heat transfer efficiency of the
oven, and the type of solder paste that is used. The optimal soldering profile that is used must be
trimmed for each case depending on the specific soldering process and PCB layout.
⚠
The target parameter values shown in Table 6 are only general guidelines for a Pb-free process.
The given values are tentative and subject to change. For further information, see also the JEDEC
J-STD-020C standard
[3] .
Process parameter Unit Target
Pre-heat Ramp up rate to T
SMIN
K/s 3
T
SMIN
°C 150
T
SMAX
°C 200
t
S
(from +25 °C) s 150
t
S
(Pre-heat) s 60 to 120
Peak T
L
°C 217
t
L
(time above T
L
) s 40 to 60
T
P
(absolute max) °C 245
Cooling Ramp-down from T
L
K/s 4
Allowed soldering cycles - 1
Table 6: Recommended reflow profile
Figure 12: Reflow profile
☞
Lower value of T
P
and slower ramp down rate (2 – 3 °C/sec) is preferred.