Surface Mounting Guide
Recommended Soldering Profiles
Recommended Reflow Profiles
REFLOW SOLDER PROFILES
275
Maximum Reflow Profile With Care
Recommended Pb-Free Reflow Profile
Recommended SnPb Reflow Profile
AVX RoHS compliant products utilize termination
finishes (e.g.Sn or SnAg) that are compatible
with all Pb-Free soldering systems and are fully
reverse compatible with SnPb soldering systems.
A recommended SnPb profile is shown for com-
parison; for Pb-Free soldering, IPC/JEDECJ-STD-
020C may be referenced. The upper line in the
chart shows the maximum envelope to which
products are qualified (typically 3x reflow cycles
at 260ºC max). The center line gives the
recommended profile for optimum wettability and
soldering in Pb-Free Systems.
250
225
200
175
150
125
100
75
Preheat
Reflow
Cool Down
50
25
0
20
40
60
80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420
Time / secs
Preheat:
The pre-heat stabilizes the part and reduces the temperature
differential prior to reflow. The initial ramp to 125ºC may be
rapid, but from that point (2-3)ºC/sec is recommended to
allow ceramic parts to heat uniformly and plastic
encapsulated parts to stabilize through the glass transition
temperature of the body (~ 180ºC).
Wetting Force at 2nd Sec. (higher is better)
0.40
0.30
0.20
SnPb - Sn60Pb40
Sn - Sn60Pb40
0.10
0.00
Sn-Sn3.5Ag0.7Cu
Sn-Sn2.5Ag1Bi0.5Cu
Sn-Sn0.7Cu
-0.10
-0.20
-0.30
-0.40
Reflow:
In the reflow phase, the maximum recommended time
> 230ºC is 40secs. Time at peak reflow is 10secs max.;
optimum reflow is achieved at 250ºC, (see wetting balance
chart opposite) but products are qualified to 260ºC max.
Please reference individual product datasheets for
maximum limits
200
210
220
230
240
250
260
270
Temperature of Solder [C]
IMPORTANT NOTE: Typical Pb-Free reflow solders have a
more dull and grainy appearance compared to traditional
SnPb. Elevating the reflow temperature will not change this,
but extending the cool down can help improve the visual
appearance of the joint.
Cool Down:
Cool down should not be forced and 6ºC/sec is recom-
mended. A slow cool down will result in a finer grain
structure of the reflow solder in the solder fillet.
WAVE SOLDER PROFILES
For wave solder, there is no change in the recommended
wave profile; all standard Pb-Free (SnCu/SnCuAg) systems
operate at the same 260ºC max recommended for SnPb
systems.
Recommended Soldering Profiles
275
225
175
Preheat:
This is more important for wave solder; a higher temperature
preheat will reduce the thermal shock to SMD parts that are
immersed (please consult individual product data sheets for
SMD parts that are suited to wave solder). SMD parts should
ideally be heated from the bottom-Side prior to wave.
PTH (Pin through hole) parts on the topside should not be
separately heated.
125
Wave
75
Preheat
Cool Down
Wave:
25
250ºC – 260ºC recommended for optimum solderability.
0
50
100
150
200
250
300
350
400
Cool Down:
Time / seconds
As with reflow solder, cool down should not be forced and
6ºC/sec is recommended. Any air knives at the end of the
2nd wave should be heated.
75
KYOCERA AVX [ KYOCERA AVX ]
