SMT tape :SMT's failure-reducing approach to manufacturing, handling, and printed circuit assembly (PCA) testing puts a lot of mechanical stress on the package, leading to failures. As the grid array package becomes larger, it becomes more difficult to set the level of security for these steps. Over the years, the use of monotone bending point testing, described in IPC/ jedec-9702, monotone bending characteristics of horizontal interconnections of plates, has been a typical feature of packaging. The fracture strength of printed circuit board horizontal interconnection under bending load is described by this method. But the test method cannot determine what the maximum allowable tension is.
One of the challenges facing manufacturing and assembly processes, especially lead-free PCA, is the inability to directly measure the stress on the solder joint. The most widely used metric to describe the risk of interconnected components is the printed circuit board tension adjacent to the component, as described in IPC/ jedec-9704, the printed circuit board strain test guide. As the use of lead-free equipment expands, so does the interest of users. Because a lot of users are facing quality problems. As interest grew, IPC felt obliged to help other companies develop testing methods that would ensure that BGA was not damaged during manufacturing and testing. This work has been carried out by IPC 6-10d SMT accessory reliability test method working group and JEDEC jc-14.1 packaged equipment reliability test method sub-committee.
The test method specifies eight contact points arranged in a circular array. The PCA with a BGA in the center of the printed circuit board is placed in such a way that the component is mounted factor-down on the support pin and the load is applied on the back of the BGA. Place the strain gauge adjacent to the unit in accordance with IPC/ jedec-9704's recommended gauge layout. The PCA is bent to the relevant tension levels and the extent of damage caused by bending to these tension levels can be determined by fault analysis. The tension level without damage can be determined by iterative method, which is the tension limit