| | We are having some problems with "drawbridging" on 0805 film capacitors. | | We have already reduced the pad width from .050" to .040" based on input | | from vendor. Defects appear to be random as far as location on the PWB and direction | | of placement. We are considering going to a pad width of .035" or less. Is anyone running | | this type of part without any problems? Is pad size the real key? Is there a recommended pad | | size? | From my experience I have seen four possible scenario that can cause this | 1) Component solderability (Find out what the plating is on the cap) | 2) Uneven heating (one end becoming liquidous before the other sometimes caused by heavy traces or a poor reflow profile) | 3) Component placement (to far to one end) | 4) Pad layout(try reducing the pad dimension beyond the cap termination, reducing the end pad dimension will reduce the amount of surface tension) | Lots of luck | Mike
Mike covered it all. The problem should not exist. You may have hit on one other thing as solderability of end termination area though non wetting will be clearly evident.
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