Pad cratering is a mechanically induced fracture in the resin between copper foil and outermost layer of fiberglass of a printed circuit board (PCB). It may be within the resin or at the resin to fiberglass interface. The pad remains connected to the component (usually a Ball Grid Array, BGA) and leaves a "crater" on the surface of the printed circuit board. Overview Pad cratering most often occurs during dynamic mechanical events such as mechanical shock or board flexure due to In-circuit test (ICT), board depaneling, or connector insertion. However, pad cratering has also been known to occur during thermal shock or even thermal cycling. Susceptibility to pad cratering can be impacted by several factors such as: PCB thickness, PCB laminate material properties, component size and stiffness, component location, and solder alloy selection among other factors. Testing IPC-9708 provides three test methods to characterize the pad cratering of a component and PCBA: pin pull, ball pull, and ball shear testing. In the pin pull test a pin is soldered to pads and pulled until fracture. It is a useful test for all pad geometries and is sensitive to board design and materials. The ball pull test is specifically design for BGA components and has a large sensitivity to the solder alloy and joint formation. The ball shear test is also specified for BGA components and involves shearing the solder balls of the BGA. This test is typically the most convenient but is less sensitive to the design and material as compared to the ball pull test. Although IPC-9708 specifies procedures for each test type, the challenge is that no standard pass/fail criteria are defined. This is viewed as application-specific and must be defined by the user based on their design, environment, and reliability requirements. Another applicable test method is IPC/JEDEC-9702, which is a monotonic bend test method used to characterize board level interconnects. This can be relevant for pad cratering resulting from board flexure, however this test method is broader and does not specifically focus on pad cratering failure modes. Board level reliability testing is a common approach to assessing product reliability. Performing temperature cycling, mechanical drop/shock, and vibration testing is a good way to evaluate pad cratering. However, similar to IPC/JEDEC-9702, this can be cost and time intensive and does not specifically focus on pad cratering failure modes. Detection and Failure Analysis Pad cratering can be difficult to detect