Guys,
It was told to us by our assembly house that PTH/component lead ratio is too
tight for good solder fillet and to avoid solder depression (hole is not
being completely filled up). I can see there is no de-wetting either on wall
or the pin after cross-section.

I want to know what that magic number should be. I believe that clearance or
the gap between pin and hole - what is the minimum clearance recommenced and
what should be maximum clearance for better solder fillet.

Is this information available on any IPC document? I have read it but can't
remember now.

re,
ken patel


The boards I've seen after cleaning look acceptable. The fact that
the holes are not completely filled can also be caused by improper
PTH/component lead ratio. I suggest increasing the PTH diameter to alleviate
the insufficient fill.
______________________________________________________
Ken Patel                       Phone:  (408) 490-6804
1708 McCarthy Blvd.             Fax:    (408) 490-6859
Milpitas, CA 95035

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