Solder Cracks

Solder Cracks

Material Name: Solder
Record No.: 187
Primary Chemical Element in Material: Cu
Sample Type: Bulk
Uses: Etching
Etchant Name: None
Etching Method: No data
Etchant (Electrolyte) Composition: No data
Procedure (Condition): No data
Note: No data
Reference: Sridhar Canumalla and Puligandla Viswanadham, Board Level Failure Mechanisms and Analysis in Hand-held Electronic Products, Richard J. Ross (Editor), Microelectronics Failure Analysis, Desk Reference, Sixth Edition, ASM International, 2011, pp. 23-33.

Figure 5: Via barrel cracking due to PWB level mechanical loading causing electrical failure.

Figure 6: Crack in solder joint and ceramic component after mechanical shock (drop) reliability testing.

Figure 7: Crack in solder joint after twist testing.

Figure 13: Interfacial fracture resembling brittle cleavage between solder ball and pad.

Figure 14: “Mud crack” appearance of Ni fracture surface showing the poor bond quality of solder to Ni/Cu.

Figure 15: Hypercorrosion of Ni layer observed on a microsectioned sample with black pad defect.

Figure 16: a) Build-up layer cracking in a solder joint with trace and b) Optical micrograph (top view) of a sample suspected to have a broken trace after the solder ball was removed by mechanical polishing. The dotted line represents the location and orientation of a second vertical microsectioning needed to show damage under the pad.

Figure 17: a) Trace fracture accompanied by build-up layer cracking revealed in a double-cross sectioned sample (sample shown different than that depicted in Figure 18), (b) schematic showing the location of the crack in the build-up layer.

Figure 18: a) Build-up layer cracking in a solder joint with via in pad b) further damage leading to via cracking upon further exposure to mechanical drop related stresses.