Manufacturers of electronic adhesive materials require characterization of their products that are used in surface mount assemblies of microelectronic components. With rapid changes in electronics packaging designs by OEMs, new adhesives are formulated to address them. Measuring the bond strength of adhesives is considered one of the essential metrics to characterize different formulations. A lap shear test is recognized as one of the methods to mimic real-life loading conditions. The test uses two samples, or specimens, which are bonded together before applying tensile force to pull until shear occurs. Some of the standards, such as the International Electronics Manufacturing Initiative (iNEMI), offer recommendations to perform a lap shear test in characterizing solder alloys, such as the SAC alloy (Sn, Ag, Cu) used in solder paste.
Instron’s 5900 Series single and dual column systems are built to perform lap shear tests based on load capacity requirements. Various gripping techniques, such as manual wedge action grips and pneumatic side action grips, are offered with the system to align and hold the specimen in position. Bluehill® Universal software is used to create test methods for running the lap shear test and for measuring maximum strength to shear off the specimens bonded. Furthermore, for qualitative analysis, the TestCam feature is offered for real-time feedback of the actual test at various loading conditions.