What are some of the mechanical stress considerations when mounting iSensor devices?

Packages with small lead structures can be fractured by any process that causes printed circuit board (PCB) tourque. This flexing, or bending of the PCB, can result in fractures and device separation.

Do not assume that the PCB score and snap processes are benign. It is very difficult to quantify the amount of stress it can place on a single lead. The iSensor LGA evaluation boards use a routing bit and clamping system to greatly reduce stress on the lead structure during PCB separation. The use of underfill systems, such as Hysol 4450, can increase the attachment area underneath a device and help prevent lead fracture.