Cost-Effective localization of shorts and leakages in dies, device packages and PC boards
The Magma Scanning SQUID Microscope (SSM) HiRes is a dual magnetic sensor system that extends the SSM tool capability to dies (either on full wafers, or in complex 3D TSV or wire bond devices). Magma SSM HiRes creates current images of devices at the die, package and PC board level using non-destructive techniques. Current images can then be used in conjunction with optical fiducials and design data to localize static defects in three dimensions. The SSM HiRes combines the sensitivity of a super-conducting quantum interference device sensor, or SQUID, with a high resolution magnetoresistive sensor. This allows for a two-step approach whereby the magnetic fields generated by currents inside of the device can be mapped very quickly with the SQUID and then again with high precision and resolution with the high resolution sensor. As magnetic fields permeate most materials used in typical devices, there is no need to deprocess the device in any way to begin localizing the failure. Additionally, Magma requires very small currents, nanoamps for the SQUID and microamps for the high resolution sensor. Using such small currents can protect the device under test from further damage and may be the only option when trying to detect failures in circuits with very high resistance (>100kΩ). Typical failures that can be analyzed with the SSM HiRes tool include shorts, leakages and resistive opens. The system can be used to image AC and/or DC magnetic fields (and likewise, currents) depending on the requirements of the device.