Curve Tracing Methods
RTI’s MultiTrace Software Suite features a program called MTForms which is designed to simplify the setup and operation of the tester. The program organizes Curve tracing methods into 4 easy to configure Standard Test methods which the user can further customize. For most users, these methods are adequate to do all necessary work, however, custom configurations are also possible
The standard methods are:
- Unpowered Curve Tracing: This method is the fundamental test method and is useful on just about any semiconductor IC device for finding pins that have become open, pins that have shorted to something and pins with leakage current. The method provides flexibility to be able to select which pins are grounded, which pins are curve traced and what electrical parameters to use.
- Powered Curve Tracing: This Method powers up the device and curve traces the pins with respect to the active supplies. While collecting IV data from the pin, it simultaneously collects supply current data from all supplies including ground and allows you to display that data on the same graph as the IV trace. The resulting supply current curves contain a large amount of diagnostic information relating to both the function of the pin being examined and the bulk operation of the device. This Method is done particularly well by the MultiTrace and MegaTrace with a mature easy to configure interface rich with features the laboratory with many users need
- Supply Current Measurements: This method is a simple measurement of the supply current. The Software supports 2 standard methods.
- In the Single point method. The supplies are simply turned on and the supply current measured and displayed as a dot or single point on the graph. This method can be run in a continuous loop allowing the operator to change logic levels on input pins to see how the supply current changes. This method is excellent for emission microscopy and searching for IDDQ core faults.
- In Ramp VDD mode, one supply is varied while the others are held constant. This method allows for investigations of relative supply currents, domain to domain protection circuits and stimulation of supply current leakage.
- Latch Up Testing: This software option test is used by reliability engineers to qualify parts as resistant to CMOS Latch Up. It may also be used by FA engineers to characterize control samples when a failure device is suspected of failing from latch up. Some engineers will capture emission images when the device latches up to learn what structures are susceptible. Power supplies are already bipolar so testing devices with positive and negative supplies is no different than testing devices with 2 positive supplies. Supplies do not need to be referenced to a fixed ground.