Measurement of solder paste component retention properties

Systematically evaluated the IPC-SP-819 tack test method. The study identified the factors that influenced the measurement and estimated their effect on the tack strength. An alternate tack test method that uses a shear tester was identified. Tack life measurements were conducted for six different solder pastes using the IPC, the modified IPC, and the shear tack test methods. The test results were validated by subjecting the slugs placed on the solder paste specimen to a shock test and measuring the component movement. The test validation process confirmed that the IPC test results do not always correlate to the component retention properties of solder pastes. However, the shear tack tests exhibited strong correlation. This research should enhance the knowledge of process engineers and solder paste vendors on the component retention properties of solder pastes during surface mount PCB assembly.