Hi David,
That will work; there is no reason to worry about tombstoning regards ing the
stencil opening. All the deposited solder paste will melt and distribute
regardless of the shape of the stencil opening.
It is even better if you also glue the chip down. On heating to reflow, the
adhesive wil significantly expand, opening the gap, the solder reflows, fills
the gap, and solidifies. On further cooling, the glue contracts further
compressing the SJ, which is very good from a reliability point of view.

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, Cell: 386-316-5904
E-mail: [log in to unmask], Website: www.engelmaier.com

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