Sm. Heinrich et al., IMPROVED YIELD AND PERFORMANCE OF BALL-GRID ARRAY PACKAGES - DESIGN AND PROCESSING GUIDELINES FOR UNIFORM AND NONUNIFORM ARRAYS, IEEE transactions on components, packaging, and manufacturing technology. Part B, Advanced packaging, 19(2), 1996, pp. 310-319
Two models are presented for analyzing ball-grid array (BGA) solder in
terconnects: a) A model for predicting solder joint geometries after a
n upright or inverted reflow process and b) a reliability model for es
timating maximum shear strain and fatigue life under a global thermal
mismatch load condition. The reliability model includes a newly derive
d closed-form expression relating the maximum shear strain in a solder
joint to the load, material, and joint shape parameters, The models a
re used to generate design/processing guidelines that may be used to i
mprove the yield of a BGA soldering operation and the inservice reliab
ility of the interconnect, potential benefits of using a nonuniform ar
ray (i.e., one including joints of different size and shape) are explo
red.