Hi Arturo,
I have answered your question inthe past:
There is no pull test specification. And there is a good reason none exists.
First, there cannot be such thing as a real 'lead pull test;' while you are 
of course pulling on the lead, what you are doing to the solder joint is 
peeling it—the proper reference is a lead-peeling test. 
Second, the solder joint strength, as determined by a lead peeling test, has 
no bearing on the reliability of the solder joint, provided the peeling test 
does not reveal inadequate wetting or poor metallization, e.g., 'Black Pad.'
Third, in a peeling test you always need to observe the whole peel-load 
history for the whole peeling process; with a 1T or larger heel fillet, the largest 
load will be at the initial portion of peeling through the heel fillet, with l
ower loads subsequently depending on whether or not (or to what extent) side 
fillets are present. 
Fourth, the fracture surface of the peeled solder joints give typically more 
information than do the peel-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.
Fifth, the reliability in actual use does to a large extent depend on the 
heel fillet and the 'bottom flat' wetting; if the foot length is <3W, than also 
on the presence of a toe fillet, because short feet 'rock' during thermal 
cycling. Side fillets are less important, unless you have wetting problems.

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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