Hi Jesse,
There are no pull/peel/shear test specifications. And there are good reasons
none exists.
First, the solder joint strength, as determined by a shear test, has no
bearing on the reliability of the solder joint, provided the shear test does not
reveal inadequate wetting or poor metallization, e.g., 'Black Pad.
Second, in a shear test you always need to observe the whole shear-load
history for the whole shear process; the loads required for the shearing process
will vary with the size of the fillets. In many cases larger fillets are bad
due to higher propensities for tombstoning and component cracking.
Third, the fracture surface of the sheared solder joints give typically more
information than do the shear-load histories, because the ONLY really
important finding is whether or not adequate wetting has taken place, i.e. the
separation is mostly in the solder vs. being interfacial.
Fourth, the reliability in actual use does depend mostly on the thicknes of
the solder joints underneath the components--thicker SJs would actually reduce
the shear-loads required for the shear process, while they give better
reliiability.
Regards,
Werner Engelmaier
Engelmaier Associates, L.C.
Electronic Packaging, Interconnection and Reliability Consulting
7 Jasmine Run
Ormond Beach, FL 32174 USA
Phone: 386-437-8747, Fax: 386-437-8737, Cell: 386-316-5904
E-mail: [log in to unmask], Website: www.engelmaier.com
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