A medical device manufacturer was experiencing 4% field failures on handheld monitors (failed BGA joints). They downloaded an and implemented a strain gage test on their depanelization router.
The standard specifies exactly how to set up your strain testing to ensure accuracy: Strain Gage Selection : Recommends three-element stacked rosette gages ipc-9704 pdf
, formally titled "Strain Gage Test for PCB Assembly During Manufacturing and Handling" , is a standard developed by the Association Connecting Electronics Industries (IPC). It focuses specifically on measuring the mechanical strain placed on printed board assemblies (PBAs) during key manufacturing steps. A medical device manufacturer was experiencing 4% field
In short, IPC-9704 is the difference between a product that lasts for years and one that fails because of a single, invisible bend. ipc-9704 pdf