As the world continues to work through the pandemic and through the semiconductor shortage, it is more important now than ever to make the best use of our human resources. One way to do this is by giving them the proper tools to work quickly and efficiently with the best technological resources available. In the world of failure analysis (more specifically, curve tracing), the hardware, software, and ongoing support offered by RTI’s MultiTrace and RTI’s FA-centric test fixture products can make that happen.
In the failure analysis lab, the curve tracer is indispensable. In many organizations, they perform curve tracing on every device that enters the lab, and it is virtually the first test performed. Having an efficient curve tracer can be an enormous advantage in the lab and to semiconductor OEM companies. Powerful automated testing leaves more time for skilled activities such as fault localization and sample prep instead of labor-consuming manual curve tracing tasks.
Virtually every FA lab has some kind of manual curve trace setup comprising an old curve tracer with a CRT screen, a manual switch box, a DUT board, or a breakout board. RTI still supports such setups with new switch boxes, cables, and DUT boards. But RTI also has revolutionized curve tracing for over 40 years by offering fully automated and software-controlled curve tracers that can do more in less time than any manual setup ever could.
Manual curve trace setup: curve tracer with RTI’s manual switch box and dedicated R1 breakout fixture
Manual curve tracing is often limited to unpowered curve tracing applications. The curve tracer itself may be 40 years old with a CRT screen, which does not offer a way to capture the image digitally on the tool itself, so most of the data is collected photographically. This leads to limited data sets based on time and resources available. RTI’s MultiTrace breaks this limitation by reducing the setup and testing time allowing the operator to test devices faster and allowing the operator to save and compare large batches of curve trace results simply and efficiently. The MultiTrace also has a wide range of test methods that are simple to configure using the software but would otherwise be too complex to configure in any other manual setup.
Automated curve trace setup: MultiTrace with PGA-625 fixture (bottom right) and 1152 octopogo fixture (center)
For the FA lab, the unpowered curve trace is King. The opens, shorts, and leakage evidence it provides is the core of many analyses and leads to the localization of most defects localized to the pad structures and package construction. The MultiTrace makes this efficient through a simple user interface, logical easy to configure test conditions, and means to save and recall any aspect of the test setup or results.
Advanced Test Methods with Powered Curve Tracing
RTI’s 950 series fixtures are capable of stimulating or powering up devices for powered curve tracing tests
Powered curve tracing is one of the most diagnostic-rich tests one can do on a device short of a functional test. With this method, the analyst can assess supply current on multiple power domains, evaluate parameters found in the DC specifications table of a typical datasheet, and characterize input and output pins in the proper bias state.
The ability to correlate supply current changes with IV curve trace reveals a trove of information about how input pins switch and core circuit blocks turn on and off that often is key in solving a failure analysis mystery.
The conventional use of curve tracing is for characterizing the electrical response behavior of failed pins with respect to good pins. The MultiTrace excels at this, but its usefulness does not end there. Stimulating the device during the execution of fault localization methods is very useful, especially when performing optically based imaging techniques. When a leakage or high supply current test condition is discovered, it can be stimulated again while being looked at with the right camera. Thermal emission or hotspot testing has several forms, but most require the device to have electrical stimulation relevant to the failure. Since curve tracing is the means by which the leakage is found, it makes sense to use it again to bias the failure during these techniques.
FA Fixtures and Support
Double DIP adapter with test socket
Side-by-side adapter for PGA-625 MultiTrace fixture
RTI offers a wide range of fixtures compatible with the MultiTrace no matter which interface or pin count the system has. The most common product is test sockets with open top and open bottom features along with DUT boards that interface the socket to the curve tracer. RTI offers configurations for benchtop and microscope stage applications, and we can make a test socket interface to any system and for any device.