IPC-7530A Draft Document for Industry Consensus Only August 2016 creating defects (e.g., bridging, icicles or opens). Wave shape and width are important variables to keep in mind when creating a thermal profile because they influence defects such as icicles and bridging and to some extent dwell time, which is also determined by the conveyor speed.
5.5 Profile Development Steps
The development of a wave soldering thermal profile should include the following. See Table 5-1 for a summary of mass wave soldering parameters. A profile consists of 3 phases: preheat, soldering and cool down (see Figures 5-3 and Figure 5-4).
• Select solder alloy and flux; identify key limitations
• Review component specs; identify key limitations
• Review substrate specs; identify key limitations
•
Determine web width and calculate conveyor speed
•
Select preheat zone temperature settings
• Select solder pot temperature setting
• Select cooldown settings (if available)
Table 5-1 Mass Wave Soldering Parameter Summary
Profile Topic
Alloy melting temperature
SnPb Alloy
183 o C
Solder pot temperature
Topside peak preheat temperature
Flux activation time
250-260 o C
100 to 120 o C
60–120 seconds
Dwell Time (board thickness .060” to .090”)
Dwell Time (board thickness >.090”)
2-4 seconds
4-8 seconds
Pb-Free Alloy (SAC Alloys)
~217-227
260-270 o C o C
110 to 130 o C
60 to 120 seconds
3-5 seconds
5-10 seconds
30