®
®
Accu-F / Accu-P
Application Notes
PREHEAT & SOLDERING
CLEANING RECOMMENDATIONS
The rate of preheat in production should not exceed 4ꢀC/
second and a recommended maximum is about 2ꢀC/second.
Temperature differential from preheat to soldering should not
exceed 100ꢀC.
For further specific application or process advice, please consult
AVX.
Care should be taken to ensure that the devices are
thoroughly cleaned of flux residues, especially the space
beneath the device. Such residues may otherwise become
conductive and effectively offer a lossy bypass to the device.
Various recommended cleaning conditions (which must be
optimized for the flux system being used) are as follows:
Cleaning liquids. . . . . . . i-propanol, ethanol, acetylacetone,
water and other standard PCB
1
COOLING
cleaning liquids.
After soldering, the assembly should preferably be allowed
to cool naturally. In the event of assisted cooling, similar
conditions to those recommended for preheating should be
used.
Ultrasonic conditions . . power-20w/liter max.
frequency-20kHz to 45kHz.
Temperature . . . . . . . . . 80ꢀC maximum (if not otherwise
limited by chosen solvent system).
Time . . . . . . . . . . . . . . . 5 minutes max.
HAND SOLDERING & REWORK
Hand soldering is permissible. Preheat of the PCB to 150ꢀC is
required. The most preferable technique is to use hot air sol-
dering tools. Where a soldering iron is used, a temperature
controlled model not exceeding 30 watts should be used and
set to not more than 260ꢀC.
STORAGE CONDITIONS
®
Recommended storage conditions for Accu-F and
®
Accu-P prior to use are as follows:
Temperature . . . . . . . . . . 15ꢀC to 35ꢀC
Humidity . . . . . . . . . . . . . ≤65ꢁ
Air Pressure . . . . . . . . . . 860mbar to 1060mbar
RECOMMENDED SOLDERING
PROFILE
IR REFLOW
WAVE SOLDERING
3–5 seconds
220
260
2ꢀ0
220
200
180
160
1ꢀ0
120
100
80
60
ꢀ0
Assembly exits heat–
210
200
190
180
170
160
150
1ꢀ0
130
120
110
100
90
no forced cooldown
100°C
Additional soak time
to allow uniform
heating of the
substrate
Natural
Cooling
186°C solder melting
temperature
Assembly enters the
preheat zone
ꢀ5-60 sec.
above solder
melting point
Enter Wave
Time (seconds4
Soak time
20
80
14 Activates the flux
24 Allows center of board
temperatures to catch up with
corners
70
0
10
20
30
ꢀ0
50
60
70
80
90 100 110 120
60
50
ꢀ0
30
20
0
0.5
1
1.5
2
2.5
3
3.5
ꢀ
ꢀ.5
Time (mins4
VAPOR PHASE
Transfer from
preheat with
min. delay &
temp. loss
Preheat
Reflow
215°C
215°C
200
180
160
1ꢀ0
120
100
80
200
180
160
1ꢀ0
120
100
80
Duration varies
Natural
Cooling
with thermal mass
of assembly
10–60 secs typical
Enter
Vapor
60
60
ꢀ0
ꢀ0
20
20
0
0
10
20
30
40
50
60
70
Time (minutes4
Time (seconds4
23