4608X-102-102 Datasheet, PDF (61/62 Pages) Bourns Electronic Solutions – Resistor Networks Product Selection Guide

These are the common
methods, materials and
maximum temperature/
time parameters for
soldering and cleaning
processes:
Process Step
1. Solder Paste Printing
2. Adhesive Application
3. Switch Placement
4. Adhesive Cure
5. Flux Application
5. Flux Application
6. Solder (Reflow)
7. Solder (Flow)
8. Wash (Solvent)
9. Wash (Aqueous)
High Pressure Fluids
Ultrasonics
Max. Temp.(°C)/Time (Seconds)
Soldering/Cleaning Methods
REFLOW
FLOW
Hot Air,
Infrared Vapor Phase
Wave
Wave
(Solvent)
(Solvent)
(Solvent)
(Aqueous)
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
240/30
215/180
260/5
260/5
Material
RMA
Epoxy
Rosin
Organic Acid
63/37 Sn/Pb
63/37 Sn/Pb
ODS Free
DI H₂O; Detergent
6
Solder
Reflow; Convection,
IR and Vapor Phase
7
Solder
Flow (Wave)
GENERAL
Preheat sufficiently using both time
and temp. to bring the flux to activa-
tion and minimize thermal shock.
Consult your solder paste supplier for
the recommended profile.
RECOMMENDED
Typical IR/Convection profile.
GENERAL
For maximum component reliability
and performance, minimize the time
of temp. exposure above 200°C.
RECOMMENDED
Typical alloy is Sn63/Pb37. A typical
wave solder zone profile is 245˚C for
5 sec.
PRE-HEATING SOLDERING GRADUAL COOLING
(in air)
(in air)
200°C
230°C
100°C
0°C _{ONE MINUTE 20 SECOND}
MIN.
MAX.
Use convection or Vapor Phase when
possible and minimize the time above
reflow temperature.
CAUTION
Do not exceed time and temperature
reflow profile of 240°C for 30 sec. for
Hot Air/IR reflow and 215°C for 3
minutes for vapor phase reflow.
Minimize thermal shock by limiting
temperature ramps to 3°C/sec. and by
stabilizing board and component tem-
perature during preheating.
PRE-HEATING SOLDERING GRADUAL COOLING
(in air)
(in air)
200°C
245°C
100°C
0°C
ONE MINUTE 5 SECOND
MIN.
MAX.
CAUTION
Always preheat before the soldier
wave using the temperature for flux
activation recommended by the man-
ufacturer.
Do not exceed 240˚C peak tempera-
ture for dual wave solder process
with a flow zone totaling 5 seconds.
Minimize thermal shock by limiting
temperature ramps to 3˚C/sec. and by
stabilizing board and component
temperature during preheating.
Specifications are subject to change without notice.
89
Wash
Solvent
Wash
Aqueous
GENERAL
Use solvent cleaning primarily
for nonpolar contaminants
such as rosin based flux
residues.
RECOMMENDED
Use any suitable washing sol-
vents that meet ODS require-
ments.
CAUTION
Limit excessive direct spray
pressure to 60 psi.
Allow the assembly to suffi-
ciently cool prior to the wash-
ing operation for minimized
thermal stress.
GENERAL
Use aqueous cleaning primarily
for polar contaminants such as
organic flux residues.
RECOMMENDED
Use De-ionized or Reverse
Osmosis water with multistage
rinsing. Post bake at 100˚C for
30 minutes to remove any resid-
ual moisture.
CAUTION
Limit excessive direct spray
pressure to 60 psi.
Allow the assembly to sufficient-
ly cool prior to the washing oper-
ation for minimized thermal
stress.
Board Rework Technique
GENERAL
Excessive and/or repeated high
temperature exposure may
affect the component perfor-
mance and reliability.
RECOMMENDED
Hot air reflow technique is pre-
ferred. Use No Clean or Rosin
based fluxes only, OA fluxes are
recommended.
CAUTION
Avoid the use of wave soldering
or soldering irons as a rework
technique. Avoid repeated and
excessive temperature exposure.
337