Kenny,

Since most heating is done during contact with the wave, increase contact-time is more effective than adjusting preheat or flux. In addition to increasing the wave height you could also decrease conveyorspeed.
I assume your solder temperature is already somewhere around 250 degrees Celcius ?

Daan Terstegge
Unclassified 

>>> Kenny Bloomquist <[log in to unmask]> 10/19 2:53 pm >>>
Hi All,

I have an assembly that is a build to print so I have no control over the
design. My problem is that it's a ten-layer board with the ground pin of
every I/C tied to about four internal planes with no thermal relief around
the holes. As you might guess I am not getting any flow through to the top
of the board. In fact, it's probably not even 50%. I have tried increasing
the topside pre-heat, topside fluxing and increased wave height. None of
this has shown any improvement.

I'm looking for any other suggestions, besides redesigning the board, that
might resolve this problem.

Thanks in advance for your suggestions.


Ken Bloomquist
Sr. Principal Process Engineer
PRIMEX Aerospace Company
P.O. Box 97009
Redmond, WA 98073-9709
http://www.primextech.com 

Ph:   425-885-5000
FAX: 425-882-5786
[log in to unmask] 

Northcon/2000, Chairman of the Board
http://www.northcon.org 

Electronics Manufacturers Association (EMA), Vice President
http://www.ema-wa.org 

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