Reexamination of the solder ball shear test for evaluation of the mechanical joint strength

Abstract

Ball shear tests were investigated in terms of the effects of test parameters, i.e., shear height and shear speed, with an experimental and non-linear finite element analysis for evaluating the solder joint integrity of area array packages. Two representative Pb-free solders were examined in this work: Sn-3.5Ag and Sn-3.5Ag-0.75Cu. The substrate was a common solder mask defined (SMD) type with solder bond pad openings of 460 lm in diameter. The microstructural investigations were carried out using scanning electron microscopy (SEM), and the intermetallic compounds (IMCs) were identified with energy dispersive spectrometry (EDS). Shear tests were conducted with the two varying test parameters. It was observed that increasing shear height at a fixed shear speed has the effect of decreasing shear force for both Sn-3.5Ag and Sn-3.5Ag-0.75Cu solder joints, while the shear force increased with increasing shear speed at fixed shear height. Shear heights that were too high had some negative effects on the test results such as unexpectedly high standard deviation values or shear tip sliding from the solder ball. Low shear height conditions were favorable for screening the type of brittle interfacial fractures or the degraded layers in the interfaces.

Modified ball bond shear test for determination of adhesion strength of cold spray splats

“…The second of these might be reflective of cohesion strength. The test method is based on the ball bond shear test commonly used to test the adhesion or shear strength of solder balls in microelectronics packaging [7][8]. In place of the solder ball, our modified test is conducted on single splats, with a stylus applying a tangential force along the substrate and shearing the splat.…”

Mechanical strength and fracture mode transition of Sn-58Bi epoxy solder joints under high-speed shear test

“…However, the shear speed, which is the displacement rate of a shear ram, has not yet been fully standardized with only a range being specified for the shear speed from 0.01 to 1 m/s for the high-speed shear test. In our previous studies considering the effect of the shear speed in the low-speed shear test, we confirmed the significant effects exerted by this parameter on the shear force value and failure mode [7,8]. Therefore, the effect of this parameter on the high-speed shear test needs to be systemically investigated to elucidate the failure behaviors of the solder joints and their mechanisms under high-speed shear loading.…”

Mechanical Property Evaluation of Sn-3.0A-0.5Cu BGA Solder Joints Using High-Speed Ball Shear Test

“…[19][20][21][22] According to our previous research concerning the shear testing of ball grid array (BGA) solder joints, the shear forces of solder ball joints at various compositions increased with increasing shear speed within the range from 10 lm/s to 700 lm/s. [12][13][14] This is well explained by the aforementioned fundamental laws. In addition, this explanation is further supported by the fact that the shear strength is dominantly affected by the deformation of the pure solder.…”

“…In our previous studies examining the effects of the shear speed in the low-speed shear test, we confirmed the significant effects exerted by this parameter on the shear force value and failure mode. [12][13][14] Therefore, the effects of the shear speed in the high-speed shear test need to be investigated systemically to elucidate the failure behaviors of the solder joints and their mechanisms under highspeed loading.…”