In the F/A lab the MultiTrace and MegaTrace fill these roles:
- Incoming nondestructive electrical test: This is usually the first or second process the device is subjected to and is used to confirm the failure complaint, collect electrical evidence of the failure and confirm overall continuity of the pins. The MultiTrace offers a very wide range of test conditions to mimic the condition in which it originally failed
- OSL: Opens, Shorts Leakage testing. This tells the analyst if any pins have become disconnected or shorted to another pin. This also evaluates leakage which is when current flows when it should not. For example when a voltage below one half volt is applied to a typical diode, no current should flow. The MultiTrace can measure any leakage current down to 1nA
- Post Decap electrical inspection: In the course of analysis, the plastic package is often removed to expose the die inside. This process can be harsh involving very hot and potent acid solutions. Curve tracing after decap using the same test conditions as before decap and comparing the saved curve traces gives the analyst confidence that the failure did not change as a result of the decapsulation process.
- Optical Fault Localization: An FA lab uses a variety of high end optical tools to isolate the exact spot where an electrical defect exists. Often there is a short circuit consuming excess current and causing heat or an open circuit where the current can’t get through. Procedures looking for faint IR or visible light or ones that scan lasers across the surface are all effective at finding different types of failures. In all cases the device needs to be powered and the failure sitr biased with voltage or current for the procedure to yield any useful images. The MultiTrace is an excellent tool for biasing the device with DC test conditions. Usually, the same test conditions used to find and characterize the failure can be used again to stimulate it.