Hi, Folks,
Is there a standard that specifies how well SMT pads should adhere to
the pwb? By pads I mean BGA pads that have no trace attachment, and I.C.
(gullwing) pads.
A client has circuit boards with pads that come off extremely easily
during standard rework and reflow processes. It is not limited to the
BGA pads, many other unused I.C. lead pads are also being found out of
place in the solder joints after reflow, and are easily peeled away. The
pads are not tiny flip chip pads, but standard .035" diameter pads and
rectangular .020" by .030" pads. The reflow peak temperature is only 210
deg. C for about 40 seconds. The rework is at 200 C. for 30 seconds.
Also, any speculation on the cause? This problem is limited to a single
PWB part number.

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