All component manufacturer's that I work with have recommended profiles. Most
have charts with maximum dwell time vs. temperature, maximum thermal shock
entering the wave... Most of the larger commercial supplier's can supply you
with a summary of experimental data for specific component types.
Be careful, thermal shock performance varies by component type, size and
supplier.
Also, many solder machines on the market (especially used and bottome end
equipment) are not capable of soldering some bottom side SMD components
without exceeding reccomended thermal shock requirements.
PCB warpage in wave soldering is largely determined by panel design and PCB
fab processes. If a large ground plane is not symmetric across the whole
panel, it will warp. But the main factor is the incoming PCB. If the laminate
was flattened after HASL, for ex., wave processing may return the panel to
its original condition.
Hope this helps,
Aric Parr
Sr. Process Engineer
Eaton Corporation
1400 S. Livernois
PO Box 5020
Rochester Hills, MI 48308-5020
248 608 7780
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---------- Original Text ----------
From: C=US/A=INTERNET/DDA=ID/TechNet(a)IPC.ORG, on 7/16/99 9:31 AM:
Hello. I am trying to get our approval for wave soldering on several space
programs which are currently hand soldered. In doing so, I have been
confronted with several questions. The main areas of concern for our folks
are:
1. Does the wave solder process induce any thermal shock to the components
or exceed the thermal spec's of the components?
I realize that it will depend on the component and the wave temp, but
does anyone know of papers, doe data, etc. that I can access and mount a
convincing argument?
2. Will the wave solder process warp the PC board?
Again, what I am looking for is hard data to marshal an argument. If so,
how can we mitigate warpage?
3. For those companies that use page frames, do you wave solder with or
without a it attached? Also, is a pre-bake recommended to remove moisture?
If so, are there industry guidlines?
I realize that this is a huge request, but I would appreciate any pointers,
especially where to go to find the information.
Eric Kalgren
BFGoodrich Aerospace
Data Systems Division
(505) 938-5139
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