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Variations of Solder Joint/Ball/Bump Geometry due to Changes in Fabrication Process Parameters Soud F Choudhury Department of Mechanical Engineering University of Connecticut, CT USA soud.choudhury@uconn.edu

Abstract

Keywords: Geometrical modeling, solder balls, surface evolver, surface tension, microelectronic packaging


Underfill Epoxy

Solder Balls (SLI)

Silicon Die

Printed Circuit Board

Solder Interconects (FLI)

Substrate


vertices /* given by coordinates */ 1 0.0 0.0 0.0 2 1.0 0.0 0.0 3 1.0 1.0 0.0 4 0.0 1.0 0.0 5 0.0 0.0 1.0 6 1.0 0.0 1.0 7 1.0 1.0 1.0 8 0.0 1.0 1.0 edges 1 1 2 2 3 3 4 4 5 5 6 6 7 7 8 8 9 1 10 2 11 3 12 4

/* given by endpoints */ 2 3 4 1 6 7 8 5 5 6 7 8

faces 1 1 2 2 3 3 4 4 5 5 6 -4

/* given by oriented edge loop */ 10 -5 -9 11 -6 -10 12 -7 -11 9 -8 -12 6 7 8 -3 -2 -1

bodies /* one body, defined by its oriented faces */ 1 1 2 3 4 5 6 volume 1


µ

μ


µN) 0.001

100 200 300

0.002

100 200 300

0.003

100 μN

200 μN

100 200 300

300 μN


0.001 mm3

0.002 mm3

0.003 mm3

120 0.001mm3 110

0.002mm3 0.003 mm3

Standoff Height (μm)

100 90 80 70 60 50 40 10

20

Pad Load (µN)

30



Project Report - ME 5155